The HXDA is my favorite PRS amp. However, one has to like old school (way pre-JCM) Marshall tone and feel.
My feeling is that a great many players admire the sounds that at least one of their fave players got through a Plexi. A few notable examples among a great many, for those unfamiliar with Plexis:
Allmans, Hendrix, Cream, Zep, Jeff Beck (Truth Album), AC/DC, Trower, Eric Johnson, Free, some ZZ Top, the Cars, some Grissom, Pete Townshend for a while, Ramones, Neil Young has used them, Slash (if memory serves), countless others from several eras. And of course, EVH used a famously modded one.
There have been Marshall reissues that don’t quite sound like the older versions to me, and of course tons of builders have tried, to varying degrees of success/failure.
I think PRS and Doug Sewell hit the bullseye with the HXDA, obviously, but I’ve tried to find my own sounds with the amp instead of duplicating others’ sounds. The beauty of the Plexi is that it’s very adaptable. A player can make it his/her own without difficulty, as most of the players in the above list did.