I can't speak from rounded experience, but I can say that it has been impossible to put Jack on a routine so far! If we wake him for a feed he just falls asleep again within seconds!
I want to get him into a routine, having read Tracy Hogg and been very convinced by her ideas and techniques but as we are currently trying to get feeding going after a slow start a routine doesn't suit us so much yet. We just have to feed him whenever he will take a feed.
I think ultimately it comes down to what works for you and your baby. I know that I struggle when he seems to demand food every hour from time to time and I trust Tracy Hogg enough to believe that he can't possibly be hungry when he has just fed well. Trouble is, atm, it's hard to tell if he's feeding well each time as we are both still learning. But if your LO only demands a feed every three hours anyway then go for it!