Depends what you are looking for!
Servicing?
General maintenance?
Tuning?
Big Power build?
There are competent people out there for the basic stuff, plus a few incompetent.
For Skyline side, there have been some around for 10+ years, like Rod Bell, RK, AMS, etc. who must be doing something right. Some newer people on the block. The 35, not yet got that sort of longevity but are getting there.
Fact is every tuner has a skeleton or two in the closet, they aren't perfect and sometimes it goes wrong. The true test of professionalism is how they respond to mistakes.
In the end, you want someone who does a reliable job, for a fair price and can be reasonably trusted - the key element. Clients by definition have to put a degree of trust in their 'tuner' and it leaves you wide open to abuse by those with an unscrupulous streak. Been there, done that, suffered the consequences.
DaveG