FMOTP
I'm a big Porcupine Tree fan. I think anything they put out is at worthy of our attention. However, I do prefer the later releases, from SIGNIFY forward. I think the DELERIUM EP is a bit redundant. For my money, the better tracks are "Signify" and the full-length version of "Radioactive Toy". "Signify" is the most "metal" of the four tracks, although I prefer the COMA DIVINE version. "Radioactive Toy" starts slowly but has a great guitar solo.
However, all of this material is available on other PT albums. There's a good chance that fans of the band already have these songs. A search of Ebay and Amazon suggests that this EP is probably difficult to find. The band later released a more comprehensive "Delerium Years" collection. This EP probably holds the most value for fans who don't already own these particular songs.