DS2 is now 11 weeks and feeds have gone from 45 mins to about 5 mins, 10 mins max. He takes about 15 mins to drink a 6oz bottle so these short feeds seems tiny. He's a drinker so once he has done gulping he comes off. I generally try and get him to have some more but he isn't interested and even his night feeds are no more than 15 minutes from wake up to back in cot.
He was a slow gainer at first, at over 3 weeks was only 6lb 10 but last weigh in at 9 weeks he was 10lb 5 in 6 weeks gained nearly 4lb and has gone from the 0.4 - 9th centile. He is only pooing once every 2 days or so and has one bottle of FF a day.