Mep, I haven't directly compared them, there is probably a US pressing of this album here somewhere. I think the early Islands were great, sonically- the problem is that the pink labels tend to be a little noisy and are hard to find in great condition, short of paying very high prices for what amount to collector records. The first pressings of King Crimson on Island are pretty obscene, pricewise. The ELP album is one which is not ruinously expensive as a first pressing. The trick is then condition. I also got a pink label of Stand Up by Tull. The later pink rim issues are good, far cheaper, tend to be quieter, but don't have the richness and depth of the earlier pressings.
My previous experience with these extended to that old warhorse, Tea for the Tillerman. I had the original UHQR that I bought new and it was sonically inferior to the pink rim which I bought years later off the street from a homeless guy. I eventually got the pink label of Tea- unfortunately my copy of that is on the noisy side. (I'll have to clean it using the AD and see if it improves). I've recently bought some old Traffic pink labels to add to the pink rims I already have.
But, there are exceptions. I have an almost endless number of different pressings of Aqualung. It was also issued on Island as a pink rim; I have the old MoFi, some early Reprise pressings and the DCC. A friend brought over his WLP copy, which sounded the best. I managed to track that one down- so in that case, the earliest U.S. pressing seemed to beat the others including the Island (which, as far as I know, was never released as a pink label, only a pink rim).
PS: On the Island pink label and rim pressings, I am referring to the UK ones; they were pressed in plenty of places in Eu- I don't have much direct experience with the German copies, which - at least on other labels, can be good.
PPS: on ELP, according to one guy I trust on another forum, the matrices of the pink label and pink rim are the same, so unlike other pink label v rim, there may be little sonic difference, I don't know. (Usually the rims are cheaper).