I have the FC2 Platinum and two seasons of use. It requires quite a few stakes when the fly is used, but I also leave the fly off on mild nights. It's tight but workable for two and spacious for one. The front entrance isn't as convenient, especially with the fly closed all the way.
So there are tradeoffs for the light weight but they're mostly worth it. Will add that it fits into tight spaces many tents won't.