I'm looking to upgrade an older bike to STI. My budget, and common sense, dictate used, early equipment, which is plentiful on eBay. I've been going between Shimano RX-100 and RSX but am leaning towards the RX-100 because I'd really prefer 8x2 to 7x3. It also appears that the RX-100 was simply a better group than the RSX. I'd love to hear from anyone who has experience riding either or both groups.