You get what u pay for at the end of the day a local lad has one on a Vauxhall z20let, it makes the power but smokes badly and uses loads of oil, also the power band is 5500-6500, pretty rubbish really and that's with a decent well known mapper.another mate had one on a slightly modded cvh and that was similar, mental lag.
I've had genuine t4, gt30 and now borg Warner on my Cossie and the Borg Warner is worth the extra money even on an old l8 ecu it's awesome.