The only problem I see with the length is when you combine it with the achievement that requires you do collect all the baubles. That just makes it horrible - miss a bauble or get kicked out of the zone for some reason and you've wasted a couple of hours.
Finally finished tribulation last night - clearing 2-2 on tribulation was nasty, but I think if I went back again I could do it in 45 minutes or so. 2-3 tribulation is quite easy once you know the route, with the exception of that slippery room 2/3 of the way through with the NO clouds and wind doors and 1shot spikes everywhere. That was just brutal.