I have used all these papers and would agree with bdial's ranking, but would add that there is a considerable gap in warmth between MGWT and the others. MGIV and MCC are very close in appearance, with MCC just a hair (or maybe two hairs?) warmer. Printing the same image on both papers and shuffling the prints, I can tell which is which, but not without careful scrutiny. I would describe both of them as neutral papers. Ilford's warm tone is in an entirely different category. I know that some complain that it is not warm enough, but side by side with either MGIV or MCC, the warmth is immediately obvious. It starts with the paper base, which may be whiter than it used to be, but is clearly not the bright white of the neutral papers; darker tones are also clearly warmer.
Ilford's warmtone is stunningly beautiful to my eyes, and is my current favorite paper. I don't print everything on it as some images seem to want to be cooler. (And, as you've noted, MGWT is pricier; it's also considerably slower.) For those I use MGIVnot because it's better than MCC, but because I find it easier to move back and forth between the two Ilford papers.
--Ben