Originally Posted by
tadawdy
The biggest problem with Sora, aside from the fact that I also find the shifter design annoying (also have heard the thumb button likes to break), is that you will constantly be adjusting it. I've used it enough to believe this to be true. Even with my 105's the rear stays in adjustment fine, but the front is still pretty finicky.
I have 7-sp 105 with Sora brifters on what is now my on-the-trainer-in-the-basement-bike; ran the Sora brifter combo about 5 yrs on the road with lots of mileage. It still shifts better with less adjustments than my now-on-the-road-bike that has 10-sp Ultegra. The old bike is close to 20 yrs old, and still runs on the original derailleurs, BB, crankset and brakes. Everything that wears (chain, cassette, chainrings, brake pads) has been changed countless times. Have not broken thumb button - I see the part is small, but not sure what sort of manoeuver you'd need to perform to hit something that's inboard of the brifter, other than catching the brifter on a pole or tree.
As for the OP, best is to upgrade as things wear/break - which will probably be many many years for many many parts.