For a while I used to do a 90 minute commute, which involved 2 trains, though I was only actually on a moving train for around 35 minutes or less. On some occasions I was able to get a lift, which presented both a time saving and a huge money saving (as rail fares are disproportionately high here).
My current commute is only 10 minutes
My commute is 15 steps. This tipples if I go make a cup of tea first, otherwise my secretary brings me one about an hour into the day
I would say 90 minutes is too long and should not be done except if there is no other option, and not long term.
My shortest commute in London was 35 minutes walking (longer on the bus or tube), my easiest was 65 minutes -- 55 minutes of that on the central line, plus an average 50 minutes wait, and 2 minute walk at each end, and my nicest was about 90 minutes, 45 minutes on the train, 10 minutes bike at one end, 30 minutes bike at the other.
I'd far rather commute for 110 minutes each way on an Electrostar from say Battle to Charing Cross (a 90 minute train ride, assuming an office in a 10 minute walk of CHX and a house within 10 minutes of Battle), or an LM350, then I would on a 50 minute ride from Twyford to Ealing and back on those horrendously overcrowded trains with a 5 minute walk at each end.
I'd rather a 110 minute commute on the Battle/London line than an 80 minute drive in rush hour too, or a 60 minute walk in the pouring rain (uphill, both ways, in the snow, with a hole in my shoe, after a 28 hour day down t'pit)
Length of commute doesn't tell the whole story.