They did my last OH, which was quite extensive, and did an excellent job.
There are a lot of "regional" shops around that are MT certified service centers, that could easily handle an OH that did not require in depth maintenance. That's where my OH started, w/Stockton Propeller - Stockton, CA. But on teardown it was determined that new custom made "ferrules" were needed to complete the OH. It was decided at that time to send the whole thing to Tiffen Aire because they have the resources & experience to get the job done.
Nothing but good things to say about how they handled my job - even though 2 sets of custom ferrules had to be made (@ $1500 ea. ferrule) before the OH was complete.
Another story for another time!
I would recommend them at least as good as the factory support shop in Deland, FL.
HFS
HR II S/N 002