I don't like the Sora shifters. My sister, on the other hand, loves them. If you like the feel of the shifters, nothing wrong with Sora. Personally, I much prefer the STI shifters on Tiagra and up, so I would get Tiagra.

I have a Tiagra equipped bike and an Ultegra equipped bike. Are the Ultegra components nicer? Yeah, they do have a bit nicer feel. Am I unhappy about the Tiagra components when I ride my Tiagra bike? No way! They work great.