Originally Posted by
Stratocaster
Spoke to the owner of a lbs - he said that there really isn't much (if any) difference between 105 and Ultegra.
I spoke to the owner of another lbs - she said that the jump between 105 and Ultegra is the biggest among the Shimano groups.
My Felt Z85 has 105, and I can't imaging anything shifting much better than that. Smooth, quick & quiet. What more would I want?
Owner B is lying to you. Jump from Sora to Tiagra is the biggest jump in the current generation. Once the R3000 Sora group is out , the biggest jump will be Claris to Sora