I was very fortunate to have had 2 years flying a DR500, prior to that I had flown 4 club PA28's. In my humble opinion the Robin was in a different league.
It couldn't carry as much as the arrow, from memory, I think the best cruise was a few knots slower than the latter, but for me the Robin was absolutely superb
and I miss it, wouldn't say that about any of the 28's.