i'm on laptop now, so i can reply fully.
basically i had a ceramic ball baring turbo from unknown origin, i doubt it was a turbonetics, but maybe a copy. now it failed more than likely due to the oil seals being blown open by too much oil pressure as it didn't say to fit a restrictor.
that said i was talking to a turbo re-builder who basically said it wouldn't have lasted long on 2BAR, if it would last down the road at all.
the cheap t3/t4 lasted 4 months and 500 miles max before seals started to go.
gt3071r hasn't been fitted, but did make almost 420bhp on a zetec turbo setup and has done a few pod runs and just general mad driving without issue.

onto injectors, if you go too big you will have to raise the idle to keep it stable, not an issue if you plan on abusing it lots otherwise though. even though my duty is getting high on the 60lb/630cc's i can raise fuel pressure to increase output to 900cc at 6BAR. the problem with this is that my fuel pump can only provide a pressure of 8BAR and 200lph, so a peak of 2BAR boost, not a big issue and a work around the injectors not being bigger, the main reason i got them in the first place.

back to the ecu thing, totally up to your mapper or your wallet, nothing wrong with megasquirt, good interpolation between load sites, good processors on the ms2 or ms3.
the only issue is with build quality if diy and the mapper.