Personally I don't like using the brake lever to shift on the shimano, it feels a bit odd but it is handy when shifting down while braking. I personally prefer SRAM and don't like campag at all. The little thumb levers are in the wrong place and I can't reach back to them when on the hoods but if you've got little hands that may not be a problem. SRAM is simple, one lever for everything. Push it to change up, push it further to change down. Hood shape is nice I find too.
105 and ultegra are hard to beat for value though. SRAM rival can be had at a good price too.
Personally I don't like using the brake lever to shift on the shimano, it feels a bit odd but it is handy when shifting down while braking. I personally prefer SRAM and don't like campag at all. The little thumb levers are in the wrong place and I can't reach back to them when on the hoods but if you've got little hands that may not be a problem. SRAM is simple, one lever for everything. Push it to change up, push it further to change down. Hood shape is nice I find too.
105 and ultegra are hard to beat for value though. SRAM rival can be had at a good price too.