I've used both the Wylex and MK boards and would consider the MK to be of considerably higher quality than the Wylex. I've reviewed the MK on Screwfix.
I've had lots of trouble with Crabtree RCDs and RCBOs so have stopped using them for fresh installs.
After the recall issues, I'm not prepared to go back to Electrium products. I also dislike that they are very coy about where their stuff is made.
I am a big fan of the new designed Hager boards and use them almost all the time now - my local Edmundsons stocks them. And they are assembled in Telford (I'm led to believe the moldings are made there too, but cannot confirm that). The devices are made in France and Germany. So far (about a dozen or so) I've had absolutely no problems. And I discovered from a recent thread that these are one of the few boards made of self extinguishing plastic, too.
My fave board is the MEM Memera 2000AD, but I don't like that you can't test their RCBOs by contacting on the screw head (MEM technical told me that's how they're designed!!) whereas you can with the Hagers. Made in the UK, but too expensive for most jobs.
Edit:
For those that might not know, Electrium = Volex, Wylex and Crabtree (also Steeple and Newlec 'own brands').