"A current SEP pilot should be able to fly any other similar SEP with little effort."
Oh, so going from a C152 to say a Tiger Moth or fast VP taildragger wouldn't take you more than just a couple of circuits then? That I would like to see!
So would I. Except a Tiger Moth or fast VP taildragger isn't similar SEP. From a C152, I would consider the following as similar (not exhaustive):
C172
PA28 (fixed gear, fixed prop)
AA5A
AA5B
TB9/10
Beagle Pup
T-67A
IMHO, none of the above should require more than a couple of hours for an average PPL to assimilate to from a C152. As soon as you bring taildraggers, retractables or wobbly props into the equation, things start to change.
