Probably a bigger issue is what is the best ring for everyday use. I think the 39T to 42T range is where you want to be. A 34T in a compact is pretty low, so you'd better be fit to turn that 50T or 52T big ring all the time.

Extra weight of a triple? only 86 grams or about 1 mouthfull of water. Shifting issues between the compact and a triple? My triple shifts like silk, the change in the number of teeth between my 52T-39T-30T is less in each shift than between the 50T-34T so I think the triple shifts as well if not better than the compact. Other issues? The triple has a chainline that is 2.5 mm different and the long cage RD weights 10 grams more. It does't bother me.

You can have your cake and eat it too. Get a triple, when you're tired of it, take the 30T ring off and set your limit screw so you can't shift on it. Now you have a double and have recovered half of the 86 grams. Plus you can always go back.

Bottom line, if you need to climb big hills and keep your cadence up in the 80+ range most of us need that granny.