Writing as one who has flown every model of RV (except the -5, and that might happen), I?d say that no, they don't all fly alike...but yes, they are all honest airplanes that aren?t out to get you. If you can fly one model, you have the capability to fly them all - but a good checkout in your first few is a great idea.
Taildraggers fly like taildraggers, nose-draggers fly like nose-draggers (just keep the weight off that nose gear!).
The differences you?ll notice are mostly in response rate for given control deflections, and the control forces themselves. Mike Seager has proven that if you can check out in a side by side two-seater, you can easily step in a tandem without a problem.
With good fundamentals, all RV?s are in reach.
Oh...the -1 was the least responsive of the line, but then...it was where Van did his learning. Thankfully, he got everything right on his very next next one, the -3!
Paul