I know I've asked something similar in the past, but:

My components are:

Ultegra BB, Rear derailleur, Front derailleur, cassette
105 Shifters, crankset
HG-73 Chain
Sora brake calipers

Is that set of components good enough to race on, or should I have spent the extra $25 to get all ultegra (Yeah I know I should have), but is that alright? If I plan on racing, will I find myself upgrading my shifters and crank to ultegra? Basically, does that setup seem ok for racing?