50/34 compact question.
 

I have a 50/36 compact crankset on one of my bikes that works really well for me. It is the same numerical difference in tooth count as the 53/39. I'm shopping for a brand of crankset for another bike that seems to be available only in 50/34. That seems like a pretty big drop for a Shimano D/A derailleur. Have they worked out well in practice? Should I bite the bullet and buy a 36 tooth chainring along with the crankset to be sure?