In order of quality and expense the ranking of Shimano components (Best to Worst) is:
Dura Ace
Ultegra
105
Tiagra
Sora
Yours ...
It looks like a decent starter road bike but a little better set of components would sure be nice. If you really ride it a lot, lust for something nicer will soon come your way (N+1 syndrome).
(All of these shifter types are indexed, meaning one tap of the shifter finds the next gear up or down... you don't have to "find" the gear by moving a lever an exact distance.)
Last edited by billydonn; 01-04-10 at 11:23 PM.