I go long on leg day (around 2 hrs) and on arm day (bi's/tri's, 2hrs) but usually just over an hour on chest, back and shoulders days. I have a 5 day training split and when I finish with legs, I hit chest the next day. There is no 'off' day for me. Every 3 weeks or so I will take a day off just because of life's demands, I get too busy.
Anyways, my point is, I have been doing this for 4 months and been making excellent gains.