RWCMD is good for some things, not so good for others.
Generally speaking, its a great place to go for a degree if you're not wanting to be a top-level soloist, but not the best choice if that's your ambition.
If you want to teach, its fine (if you want to teach within Wales, its even an advantage). Also if you want to be able to do parts of your degree through the medium of Welsh (ie, get to write some essays and things in Welsh as opposed to English), then its the only choice. Also, for people who cant cope with the thought of leaving Wales/studying in a major city, its a great other option.
Its improving in standard, but yeah.. its generally not on a par with the top level colleges, though obviously that depends somewhat on which instrument (or voice) you wish to study.
In other words, it suits some people, not others.... like any other college really!
I think the only way to really decide which college is the best, is to visit them yourself. For example, I only applied to 2 this time round.. the RCM and the RNCM. (at £50 a time for auditions i didnt fancy trying for them all

)
I absolutely
loved the rncm... most amazing vibe, and i felt like i could be happy there, and fit there.
Absolutely
hated the feel of the rcm... not because anyone was unfriendly or anything.. i just wasnt comfortable there, it didnt suit me...
My friend felt the absolute opposite - loved the rcm, hated the rncm... it all depends on your character, and your aims.
So basically, i'd suggest that its worth visiting the colleges before you apply, or if thats not possible then at least taking a good look around when you go up for audition.. try to get the feel of the place, and figure out where you'ld be happiest... it just makes such a huge difference!
hope that helps some.
s xx