I've seen the concerns but never experienced them myself.
I ordered a Sig:X out of the first batch and received it within a week. Had the Fat Mod done at Fryette a few years later and they shipped it back within a week.
I ordered an original Power Station shortly after they dropped and received it within a week. Ordered a PS-100 from Zzounds and it shipped within days of being ordered.
I picked up a Deliverance 120 used for $800, sent it to Fryette for a stem to stern checkup and complete retube, effects loop added, and footswitch jack added for a footswitchable Less/More function. They had it for two weeks and then shipped it back.
Despite the posts I've read, Dave who does Support at Fryette has been responsive to my emails in a timely manner and their repair/mod work has been exemplary.
I don't know what has caused others to experience the issues they've had or what I've done right but so far I've been very happy with them as a company.
And of course their amps have been truly wonderful.
I probably spoke about it before, but here is the TLDR version:
1. Their forum had a thread about reducing distortion in the clean channel. People suggested swapping out V1 for an AY7 tube.
2. Dave was
involved in that thread as an official representative. He never told anyone they shouldn't do this, or it would void their warranty.
3. I tried it, literally for 2 minutes. It made no difference.
4. I contacted the UK distributor at the time to try and get the amp looked at under warranty.
5. Fryette revoked my warranty because I had tried an allegedly unsupported tube - even though most amp techs suggest this kind of thing all the time.
6. I pointed out that this was unfair given that Dave was sanctioning the advise on the forum.
7. I took the amp to my tech friend instead. The distortion was coming from the Rectifier tube. It was faulty. I had no idea.
8. Fryette told me I was a liar and asked for my tech's details. I politely refused.
So that is one thing.
Another thing is, my footswitch would always randomly switch channels depending on what venue I played at. It disrupted a few gigs over the years. Fryette had no suggestions on how to resolve it, and preferred to blame the UK power network instead.