I like them both for different reasons. The TBH is easy to build, requires no lifting of supers and has all natural comb and clean wax by default.
The Langstroth in the form I'm using (eight frame mediums) requires lifting but the maximum weight per box is below fifty pounds. With foundationless frames I can get the clean wax and natural cell size. The nicest thing is if the hives are a long drive away, I can pile supers on during a flow and come back to harvest them when it's over. With the TBH I'd have to harvest several times.
I have had some comb collapse in a top bar hive. I had one that was a long deep, Langstroth sized hive and the combs went down one hot day like a row of dominoes. I had to do a cut out (cut the brood comb out and tie it into frames) to rescue the hive.
Since then I made the Langstroth dimensioned ones medium depth instead of deep and they have worked fine. I also built a Kenya Top Bar Hive with sloped sides and a shorter bar and had no problems with it either. Not that a comb never fell, but only one fell that I remember in either hive and it was honey, so I just harvested it and it didn't take out the neighboring combs.
Here are pictures of my top bar hives:http://www.bushfarms.com/beestopbarhives.htm
And my eight frame medium hives:http://www.bushfarms.com/beeseightframemedium.htm