Well, I thought I would call Jayson instead and here's what he said:
Q: Is there was a difference in performance between the 'press-on' and 'thread-on' FH for the PTR?
A: Not really.
Q: Could a local gunsmith perform the install as this would avoid the hassle of shipping the rifle?
A: A gunsmith may be able to perform the install, but more likely could be done by a machine shop.
Q: What would a machine shop need for the install?
A: Press, etc, etc (After listening to his answer I told myself I was going to send the rifle to him -- I think it would be difficult to find a local machine shop that could (competently) handle the job).
Q: Lastly...how much?
A: About $105, which includes labor, parts, and return shipping. Turn around time is about a week.
I'll probably send it off within the month and will write a follow up post with pics when I get the rifle back.