I have a 1987X and I love it so I agree that the Marshalls - especially with the new USA pricing- are great value.
But the Friedman does have a lot more flexibility with the built-in variac, PPIMV master volume, switchable bright caps on both channels etc. So I don't know if it's fair to compare the 1987x/1959HW to the Friedman. It would take quite a bit of modding to get the Marshalls to do everything the Friedman does, which add cost (and probably also devalue the amp), especially if you have to hire someone to do it.
I think a more accurate comparison would be the Suhr SL67, which has similar functionality. It's handwired and it costs about $150 more, which is actually accurate to what Friedman said the Plex would cost if he handwired it.
I'm not a Friedman fan boy (the only Friedman product I currently own is the IR-D, I recently had 2 Dirty Shirley's but sold them), but I tend to agree with his reasoning behind building the amp the way he did. PCB when build correctly is very consistent indeed.