Thought id drop in 2cents as to my experience with Hidden performance.
Ive been using Mike who works there for a number of years ever since I came into supra ownership.
Hes always gone above and beyond to explain everything, requirements etc. Always been happy to answer my panicked phonecalls when Ive broken something.
Cars been running an engine swap by mike for the last year and a half with a custom wired JZX100 chaser ecu, as a testament to his dedication to my project he managed to do the entire engine swap in 4 days flat which would be hard to better anyway. So that's from a NA 2j to a 1jz vvti and everything associated in 4 days flat!