In reply to cha1n:
Very different areas IMHO. Frankejura is nearly all single pitch, shortish picthes at that, whereas the Ecrins has much more variety and the opportunities for mountains.
Frankenjura:
Lots of pocketed limestone, great if you're strong.
Or great to get strong.
Better beer.
Not much chance of getting a suntan (compared to Ecrin) due to trees
No mountains.
Quite a lot of overhanging powerful bouldering.
Ecrins
Loads of variety I imagine. From my experience, lots of granite slabs, granite boulders.
Lots of amazing multi pitch
Better rest day options - rafting, biking, walking.
It really boils down to whether the thought of powerful short limestone routes appeals. If so then go. If not then go to Ecrins.
PS, I love both areas. Done maybe 30 days in Ecrins and maybe 100 in Frankenjura.