One big difference is you better not show up more than 20 minutes late or you’ll forfeit (0 minutes in FIDE).
The game could also last a very long time if it went into the endgame.
You can take a quite healthy nap during Game 180 + 30i or d5 and still have time to play. 
I do not recommend such a lengthy time control. 4 hours is enough time to play a quality game of chess; therefore, Game 120 with delay or increment is enough. You have the flexibility to think as you wish, and you will likely not be outsat by an opponent. One time pressure period is enough stress, especially for the older player.
My recommendation to players is to go to the bathroom with 30 to 45 minutes on their clock before the end of the session. The problem with Game 90, Game 30 with either delay or increment is that you will not really have time to get refreshed. A 10 minute break to go the bathroom, grab a snack and a drink, and gather yourself puts you into time pressure in the second time control right off the bat. That is two major stress periods during the game with advantage to the younger competitor. Great for the TD, not for the players.
Harold, I think you’re misinterpreting the FIDE rule on showing up late (I believe it has been modified.)
We’ve seen a few events with 90 seconds of increment, but most events use 30 seconds or less.
As of July 1, 2014, the “zero tolerance rule” was modified. Before, the “default time” was zero unless the rules of the competition specified otherwise. Currently, the rules of the competition must specify the default time; there is no “default” default time (sorry for the awkward wording).
I recently became a TD; so I have been lurking in order to learn. Why don’t we admit the truth: The real purpose of the
the delay is to shorten the game.
Perhaps i am getting old; I grew up on 50/2 25/1. I understand that we are trying to keep youth members but we are not. The most active part of the membership is 50 and over.
We continue to shorten T/C’s and encourage bad play
First, Mr. Bell, thank you for becoming a TD.
Second, I feel your description of “the real purpose of delay” is in error. Tournament time controls were getting shorter and shorter long before delay was introduced. As you say, you recall a time when the standard control was 50/2, followed by 25/1 repeating. While that is somewhat before my time, there were still plenty of events with non-SD time controls when I started playing. Now, there are virtually none.
Now, I was around for the advent of delay. The purpose of delay, as I understand it, had nothing to do with shortening the game. Rather, the idea was to give players in SD time controls a tool through which they could decide the game on their own, without a need for insufficient losing chances claims.
That said, if you want to run longer time control events, feel free to organize them. 
Please accept my best wishes for your continued efforts.
Have you ever tried playing two games a day at those infinite time controls? I did, thanks to organizer Jerry Weikel in Reno. First game started at 10am, was adjourned a little after 4pm, per tournament rules. Second game started at 6pm and went until shortly after midnight. The adjourned game resumed about 30 minutes later, about 12:45am, and went for almost three more hours. Game drawn by 50 move rule (and mutual fatigue).
By my count, that was 225 moves and 15 hours of play in one day. There were exactly four people in the playing hall at the end. One was a very diligent spectator. The TD was catching a few zzz’s on a nearby table. After we all got to bed after 4:00am, the morning round the next day was at 9:30.
That was the last year that Weikel used infinite time controls. He learned the lesson the hard way. Now the games feature sudden death (with 5 second delay) at the end of six hours of play. While 12 hours of chess in one day is a lot, it sure beats having to complete an adjournment afterwards!
Do you still want those 25/1 time controls?
Michael Aigner
That is a good point, and that may well be the intended purpose of delay. In final analysis, the 5 second delay steals
time; you don’t regain the 5 mins until move 60
Forgive me, Mr. Bell, but I’m unclear on how you reached this conclusion. Delay stops a clock from running for a prescribed period of time. Such a function, by definition, does not “steal” or reduce total reflection time.
For example, how is 40/120, SD/60, d5 any shorter than 40/120, SD/60, d0? If anything, the first time control is likely to make the game last about 10 minutes longer.
Now, there was a time when it was common to adjust the primary time control by taking five minutes off - say, 40/115, SD/60, d5. This was done, at least in part, to keep two-round-a-day events from having more than 12 hours of play in a single day (which would have endangered the validity of norms made in applicable events). However, even in this case, the delay doesn’t “steal” any time.
If I’m misunderstanding you, I apologize, and would welcome a clarification.
Sir:
Believe me I do understand the need, for various reasons. I have adjusted, but I can’t even get people to yield to G/2
vs game 90.
Nigel Short is of two minds on this; The 90/30 t/c is tooe short for a decent end game, but the two games per day is torture
I apologize i am a beat behind. It is the method by which
delay is applied. 40/80 becomes 40/75 d5 you regain
the 5 mins at move sixty. The taking 1 min for each second
is a suggestion but it has become the rule
It’s not the rule. In fact, isn’t it now considered the exception? I know a lot of people used to do this but I don’t and I know a lot of others who don’t either.
No. This has explicitly become outlawed by the delegates.
Alex Relyea
And it was never a requirement, only an option, although its widespread use in CCA events confused folks into thinking otherwise.
Common exchange from the era, had more than once:
BTP: “Reset your clocks to two hours. 1:55 is incorrect.”
Players: “But don’t you have to deduct five minutes?”
BTP: “Only at my option, and I opt not.”
Players: “But we were told to do this at the Atlantic Open!”
BTP: “Do you see Bill Goichberg here?”
Players: “No.”
BTP: “OK, then.”
You are correct Mike. The preference is to NOT deduct any time.
The time deduction was actually an attempt to equate the use of a delay capable clock and an old analog clock. No we set the time the same regardless and those using older, non-preferred equipment are at a modest disadvantage. Of course we also promote the use of standard digital equipment in place of analog clocks by allowing for the digital to be used if supplied by white even if black wants to use analog - and even to replace an analog clock if a player shows up late with a digital clock and an analog clock is already running as long as both players have not moved yet.
It’s not a preference. It’s the law.
And it has greatly reduced clock setting errors. I got used to having to tell people in a G/120 time control to change their GameTimers/Excalibers from 155 minutes to 115 minutes, and people with Chronoses to changed them from 1:15 to 1:55. Now it doesn’t happen as often because saying two hours will get almost all digital clocks set to either 120 minutes or 2:00 (I do occasionally have to correct 200 to 120 or 1:20 to 2:00, but there are fewer corrections than before).
It is the rule not to have any difference in time between digital and analog clocks.
What I meant was, one is certainly free to use a 40/75 d5 if desired. But if you are trying to have a 40/80 tournament, then just do that.
sorry - my wording was not elegant.
I soooooo agree with Dennis!!