I had an MGC for about a year and learned to tolerate it, then finally got a WRM a couple of months ago. It came a little too tight, I adjusted it about a half turn on each side (I agree, it was hard getting the center caps off), and now it's way better than the MGC. Now I hate solving the MGC, it's so inferior.
The WRM 5x5x5 is still not very forgiving with bad alignment - the 6x6x6 and 7x7x7 are both weirdly better - but it is still the nicest 5x5x5 I've ever owned.
There sure is room for a better one on the market, though!