105 vs. ultegra ... really can't answer if one is better than the other in triple, except I have had both, with 105 in triple and ultegra in double. chain drop can be a problem in a triple, no matter what level, because of the nature of a triple -- not as smooth and quick as a double. have you looked at HOW you are shifting ... sometimes that is more the problem than the triple itself.

triple seems to come in Shimano and FSA ... the trend in newly spec'd triples seems to be 50x39x30 gearing with a 11-23 or 12-27 in rear cassette -- that seems like really good gearing if you want a lot low gears on a triple. not sure how all that works out compared to a compact 50x34 or 36 or a traditional triple of 52x42x30, but does give you more options.