CJones
Final Approach
The result is that you can never be as sure that any particular RV-8 will fly as much like any other RV-8 as you can with two PA-28-180's.
I agree that there are some flight characteristics that are different between birds within the fleet, but that is the same across the board for every model I have flown (certified and experimental). If you flew three different 180hp RV-8's in the same day you would probably experience close to the same amount of variance as you would between three 160hp 172's. Heck, I used to rent from an FBO that had three 172's on the line. Each one had their own quirks and flight characteristics that distinguished themselves. Plane 1 required a little extra trim on take off, Plane 2 had a heavy right wing, Plane 3 like to float on landing, etc. etc.
Now, if you're trying to compare a 200hp constant speed RV8 with a 160hp wood-prop RV8, then yes there will be some fairly abrupt handling differences - but that's the same when comparing a Cherokee 160 to a 200hp Arrow in my book.
I guess with everything you look at, you have to do some investigation and realize that just because it says RV8 doesn't mean all RV8's are the same, just like knowing that not all Cherokees are the same.