In my opinion yes. Tiagra 9spd is a lot slicker than Sora 2013, so if you go for 105 10 spd it would be a better bet.
My Sora 3400 broke last year and I moved on to Sora 3500 chiefly because it was inexpensive as I am thinking about replacing the entire bike. But for the extra £50 for the shifters (plus the additional costs for going to a 10spd drivertrain like front derailleur and new chain/cassette) I wish I had gone for 105.
It is ultimately your choice but all Sora 3500 will give you is paddle rather than thumb shift, don't expect it to be smoother.
I have BTW ridden with last years 105 for a few hundred miles also so I have experience of the difference.