I have the RCR-F MIPS which seems to be the same as the FCR just with MIPS. I like it so far, can’t say much about how aero it is. For ventilation I can’t say that much as I didn’t ride it in much more the. 20C except for this week and it seemed ok. But I have more vented helmet for hot/climbing days. Fits me pretty well not as well as most giros do but it’s comfy for 6h rides and more.
I may do an aero test in the coming weeks between it and the abus game changer if the weather is good and I have the time.