Tecnam have apparently decided it’s a good idea:
The normal P2012 uses the Lycoming TEO540 – the FADEC turbo engine – which seems to have mixed reviews. They’ve released this new version with GTSIO520 engines. This must be the first aircraft since the C421 with these geared engines right?
421 owners spoke well of those geared engines. Very quiet aircraft which could be flown without headsets (I have 1.5hrs in a 421C – my only ME time 
).
IIRC, one curiosity is that an A&P can install (and indeed overhaul) a non geared engine but one needs an A&P/IA to install one.
The intent is that an IA is required to overhaul a geared engine, return to service being a by product of overhaul. Any non-IA FAA A&P can indeed overhaul a non-geared engine using the MM and sign it off.
The FAA regulation on this was initiated when geared engines were typically huge ~2000 HP engines of the pre-jet era, for which the reduction units were tricky pieces of machinery that could destroy the engine quickly if something were done incorrectly. Some background here
All interesting news.
I wonder how different are the GTSIO-520S form the old GTSIO-520D’s
When I first contacted the GA scene in Mallorca, longer a go than I care to remember, one of the local schools operated a Cessna 421. Grapevine talk was that those engines were very delicate because of the gearbox, and some horror stories circulated but I could never verify them at the time. I have since learnt all turbocharged big-bore piston engines in aircraft have their caring needs. I wonder how much more the gearing adds, but it can’t be much! I still keep a copy of the POH somewhere!
Then of course one famous PPLIR member flew one around Europe as his mini personal airliner for years sharing flying stories and I dont recall a single negative comment on the engines.
I also wonder what drove Tecnam away from the TEO540’s
