I'm another who could change gear from the drops with Sora, and I don't have huge hands, am not double-jointed or a contortionist, so Sora worked fine in that respect for me.
And it's true that STI's were indeed invented so you could change gear from the bars, rather than having to go to a downtube shifter....
...which you can with Sora, so I don't see why budget-concious racers couldn't use it, even though the marketing dept at Shimano do push it as their leisure groupset.
8sp Sora did involve pretty large sweeps of the lever to change down though, so was perhaps slower going that way, but was plenty fast enough changing up using the thumb-lever.
I did replace it. on what has become my Winter bike/commuter, but it wasn't because of the thumb-lever or shifting quality.
Instead, for me I found the hoods a really uncomfortable shape, rather a strain on that web between thumb and forefinger - fine in bad weather when wearing thick padded gloves, but not good in light mitts.
I replaced them with 2nd-hand 9sp Ultegra and these are more comfortable and have the same shift mechanism as the 10sp Ultegra on my 'best' bike (so avoiding the fumbling for gears in the first 1/4 mile when I used to forget which bike I was riding...).
But (shock !) I think the actual shifting of 8sp 3300 Sora was just as good as 9sp 6510 Ultegra.
Neither is a patch on 10sp 6600 Ultegra, both are quite a lot slower, neither anything like as click-click instant gear change, both involve a much longer sweep to change down : but the Ultegra is a bit shorter sweep and is consequently heavier, particularly on the left, front changer.
Im pretty confused by it, i dont know what to do with it. It just sits in one gear, no matter how hard i push the brake levers
