RE: I have a few questions about real speed?
You know, I just read book in my LHS last week and "part" of the solution to flutter is where you mount the hinges and the rod. Sure you may never experience it and maybe you will but the location of the whole thing is a factor. I forgot the name of those books but they are all yellow on the cover and consist of many differen topics.
Also I have seen a few here at altitude with a 25fx and it was fast. Did you consider a Webra 32?