Most of the recent vinyl I've bought has been limited to releases that are were vinyl only releases, which can be really annoying if the pressings are subpar. I agree, vinyl may not be an ideal medium for very quiet music such as ambient. I first owned Aphex Twin's SAW II on vinyl, but switched to CD because the LPs were too noisy and at least one of them was pressed off center. In terms of pure sonics, though, the LP still sounds better to me, at least if you have a decent turntable. The LP pressings of the 70s were not that great because of the oil shortages of the time (LPs are made out of PVC) and tendencies of the big records companiess to recycle their vinyl (Capitol records was particularly suspect). Ironically, when CDs started to crowd out vinyl in the late 80s, LP pressing quality improved significantly with more releases being "direct metal" masters. ECM has also generally had good LP pressings, except for the brief period at the beginning in the early 70s when they were distribiuted in the US by Polydor. I have had a B&O turntable since the mid-90s and have ab'd several LP and CD releases of the same album from the 80s and have to still give the nod to LPs for sound quality.
Today, there was an interesting article about LPs and Rick Ballard's record store specializing in jazz LP's. I agree that LP's were an art form in a way that the CD is only its pale cousin. The article can be found here:http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/01/19/DDLNUFRL6.DTL