yeah i forget how you can tell if its the new computer/power or not.. i think its the first two or last two digits of the serial number of the tractor, i believe its something simple like 60 or 09 or something like that. Ill check mine and get back.
4720s went form like 58hp to 66hp, its basically the same 2.4L used in some skid steers and 66hp i think is the most theyll put out for that block. i'd have to say that i dont think its "overpowered" but rarely do i run a lot of rpms, so im usually "thinking" its got enough grunt to dig into a pile of stiff dirt.. and yet im only at 1500/1700/1900rpms... rev er up to 2500ish+ and itll manhandle just about anything.
I dig dirt piles in range B, which usually bogs, but is easy to use, range A feels like the thing is gonna burry itself and move mountains.