I stopped at Reims Champagne (LFSR) last week inbound from Salzburg, and intended to fly on to Blackbushe. I used LFSR as it has 24hr customs, but I forgot to check about fuel and as LFSR is primarily military they have no 100LL, so I had to fly on to Le2K anyway. I just filed the flight plan from Salzburg and called Reims them up from outside the Class D inbound, and this caused them no problem.
There is not much at LFSR apart from a small GA terminal with a cafe, but we were treated to an impromptu air display from about 8 Mirages around the circuit.
If you do go to LFSR make sure you have the plate with the VRPs on it and call approach in good time, as we were given a clear route to follow via the VPRs and had to hold more than once while the military landed.
I understand that Prunay is much more GA oriented, although I don't know if they can arrange customs.