Anyone own both the F/Xi3 & F/Xi5?

When I upgraded from a CSi3 to a CSi5 center, the difference was HUGE. I took the CSi3 and used it as a single rear to go with the F/Xi3 side surrounds. No longer using the CSi3 because I had to keep moving it in the room I'm using. So currently have a 5 channel setup which is perfect for that sized room. I've been keeping an eye out locally for a set of F/Xi5's so in the future (relocation, changing HT rooms, etc.) I'd have a 7 channel setup. Like I did with acoustic panels, I built more than I needed for my current small room because the opportunity was there and I figured I'd be able to use them in the future. Still have an unused box of OC703 in the garage. Anyways, to my point, I have an opportunity to buy another set of F/Xi3's locally for $100, maybe less than that. Has anyone owned both the F/Xi3 and F/Xi5 surrounds? Is there that big of a difference since it's used as a surround speaker? I'd be buying a set of speakers I currently have no use for. Would I be better off just waiting to see if a set of i5's come up in the future. I know buying a set of the newer FXiA's would always be an option if I needed them. I also wasn't sure what a fair price for a used set of i3's or i5's would be. The F/Xi3's that are local are cosmetically perfect. I would of course have to hear them to make sure they have no issues before I bought them. Also the F/Xi3's I have now are mounted on stands, I purchased them used that way and have always worried what a mess I'm going to get into trying to remove them from the stands. Looks like a double sided sticky pad (thicker than double sided tape) was used to mount them (not the best description). I was really hoping someone had upgraded their surrounds and would have first hand experience on the sound difference between the little and big brother surrounds.

Thanks.