RAM builds quite good engines...and you pay the price up front, make no mistake.
Part of that price is to advance pay any warranty claims the aircraft owner might have with his RAM overhauled engines, and yes, RAM does provide quite good warranty service.
Another option.
GTSIO engines are quite complicated internally, and do require careful pilot operation to make TBO...which they absolutely will do, IF treated properly.
Try this alternative for a GTSIO overhaul....
Aircraft of Devine Inc.
I have two of their overhauled GTSIO engines, and no problems whatsoever, to date.
On time, on budget.