This TB10 v PA28-XXX debate pops up regularly. A while ago, on Flyer I think, somebody actually got some POH figures out, and they were similar for similar fuel flows.
With old planes, it is easy to end up comparing one wreck with one slightly lesser wreck. I used to fly planes which would fly 10-15kt slower than they should, and nobody knew why, nor did anybody care.
Getting out of the self fly hire scene was a breath of fresh air...
I would expect a TB10 to fly a bit slower than an Archer, because it has a roomier cockpit.