i run megassquirt as well as karlos and a few others and has so much potential (anti lag for one e.g. launch control function, boost control, nitrous progressive control etc.)
an rs turbo box with the bigger bearings and a new main shaft will be quite strong, most of the rebuilt ones have reground shafts and oversized bearings, causing then to wear out quickly.
i got mine sorted seven years ago, ran it on 127bhp N/a and then onto 125bhp xr2 tt setup, now upgraded up to a 1.8zvh on a cossie turbo, over 200bhp, still a good solid box with no noises as yet.
although if/when it goes an mtx75 will be fitted due to it being 300bhp ready from the off.