That issue that Greyfields talks about is actually true with any form of wethering...especially when it's done too young (anything under 8 weeks in my opionion and the opinion of many, many breeders and vets is WAY too young).
Banding in itself doesn't pose any more threat for UC than emasculating. The problem lies in underdeveloped urinary tracts. The older the animal before it's wethered, the wider the urinary tract and therefore, the lower the incidence of UC.
If you band too close to the belly you can catch the urethra or other internal structures. You can also catch the male nipples, which will cause infections. We band. It works great, causes minimal pain to the goat and is very straight forward. We chose it over emasculating because once you band, you're done. Don't have to put the goat or yourself through it again.
If you want to help your little guy through the first 6 hours, give him some Banamine 30 mins before you do it.
I've only had one buckling carry on for any amount of time after it was done (but he was a sissy tee hee). Most of them whine about it for a few mins to a couple hours, then carry on with business as usual.