I have a fsa mega expo compact crank on the Bottecchia now. I want to upgrade the crankset and the BB but wonder about either a R600 I can get for $99. for go full Ultegra for about $239.

This is my second bike I ride in addition to my other and I want a better crankset but will the Shimano FC R600 be just about at good. Here is what I see for the money.
https://cgi.ebay.com/Shimano-FC-R600-...QQcmdZViewItem

The fsa I don't think shifts that great on the upshift and not nearly as smooth. Would all I need be this to get a much smoother shift. I could also go to a standard double that is $129 in an ultegra. I just have to make FD adjustments but my other bike is a standard double.

I take any thoughts or help.

I'm assuming you have the FSA Gossamer. In which case the R600 will be a huge leap forward in terms of shift quality. Adjustment quality aside. You don't gain much by going to the ultegra crank.

I recently went from an Ultegra standard to an R600 compact. No real difference in performance that I can tell. The R600 is 105 level so it is only one step below the Ultegra.