The trade items in most large caches I find these days are not that appealing. Happy meal toys for the most part. So the issue for me is not trading. There is nothing inherently wrong with micros, the real issue for me is the creativity (or lack thereof) in hiding them. Too often micros are placed in very predictable places and there is no fun in the hunt for those caches. Micros placed on a lightpole in the midde of a parking lot are a good example.
Every now and then, however, I come across a micro that either takes me someplace interesting that I wouldn't otherwise have gone to or which was hidden with a lot of cleverness and/or creativity. Those make the game worthwhile. Yes, I prefer the large caches up in the mountains, but that is because I like to get up into the mountains, not because those cache are any "better" than other caches. Those caches can suffer from the same lack of creativitiy as the micros. Unfortunately, I'm not able to get up in the mountains all that often, though, and the urban micros allow me to continue to play the game.