There may not be a huge amount of difference between Claris and Sora, but I haven't had a lot of experience with Claris. One thing that is fairly obvious is that Sora has really benefitted from Shimano's famous trickle down effect. R3000 Sora is really nice to ride IMO, a bit like 105 was in a previous iteration. For touring and commuting you can also put an Alivio rear derailleur onto a 3x9 Sora drivetrain as well, with a 12-36 cassette, and shift it with the STI levers without compatibility issues.