I am definitely a fan, and I've looked at their stuff. But I don't actually make a habit out of learning other people's music. I always feel that I start writing derivative shit when I do that
That's not really true IMO. You will carry your influences anyway. Still you can make some derivative stuff but only if you like to do so, like Dream Theater and Opeth's Benighted.
To be honest, I have trouble understanding how someone who likes sort of atmospheric, borderline prog music could NOT like Opeth. I know it's not cool to like them anymore 'cause they're popular, but man.. I just have trouble not loving that stuff.
I can tell you my opinion about Opeth, since I know the band very well and since long time ago. I knew them back on mid/late 90's(97-98) with Orchid. I wasn't impressed and I thought they were some kind of weird melodic black metal, very fragmented with terrible songwriting. At the time I was already into Arcturus, Ulver, Borknagar and stuff like that.
1999, I heard Morningrise, which I liked more than Orchid but not so much either (now I think it's terrible. I just like a little Advent and To Bid you farewell) and at 2000 I got MAYH.
That album impressed me cause the songwriting, lyrics and atmosphere are great. The harsh and soft parts flows well, it doesn't feel forced or random at all, like anything since Deliverance. Just like Borknagar's Quintessence, the non-so-great production works. I truly think this is where Opeth reached their peak at songwriting and as a creative force. April Ethereal, When, The Amen Corner and Demon of the fall are really great tracks, specially When (which is the best choice to show what Opeth is or was) and Amen - at 4:00 more or less it features the most doom moment on Opeth's entire discography (even the vocals have an enhanced reverb, to give it a spectral feeling I guess).
I can imagine why Demon of the fall is a fan fav: The massive growling at start, the verse riff is really catchy and sounds really heavy, the ending is great (it sounds really hopeless) and the lyrics. On the MAYH concept, Demon seems to be the chapter where the main character is on total dismay.
SL could have been better than MAYH but it's inconsistent, some repetitive and the quality goes downhill. The Moor, Godheads and Benighted are great tracks and no other Opeth album starts so strong as this, but after that, the rest is really subpar. Moonlapse is like a meh version of Godheads, Face of Melinda is good but Benighted does the job better with less, Serenity just plain sucks imo - with Mike rapping, awful pinch harmonics and all - and White Cluster is weak for an ending track. Until here, I would say that Opeth still wrote coherent music and this album still flows well. Also it sounds very folky, which is something that I miss.
BWP's main failure IMO is that sounds forced. The heavy and clean parts switches suddenly and just a couple of tracks built some climax well. It's very anticlimatic as a whole and there are some really bad songs, like funeral portrait, patterns in the ivy and blackwater park (a really overrated song IMO). The vocals sound forced sometimes and the arrangements are not so folk as before. Still Bleak and Drapery Falls have soul and carry a good atmosphere. Harvest is weak as ballad, too radio-friendly for my taste.
Deliverance has the main defect on the uberpolished sound. The album sounds plastic, souless and just 2 and half tracks are worthy (Deliverance, Masters and Half of A Fair Judgement). Damnation is good but it could have been SO much better, it's too simple and radio-friendly.
GR is the first really bad album of Opeth. The only completely good song there is Isolation Years, but the rest have just 'some good parts'. Here it seems to be a heavy cut/slice-paste work. The keys are awful. Some tracks are horrendous - Beneath the mire, atonement, the grand conjuration, hours of wealth, all of them are horrible. The progressions used are awful IMO.
Watershed is a piece of shit, excepting for the first half of The Lotus Eater and Hessian Peel. Coil is just an intro. Heir Apparent is meh. Burden is gay. Hex Omega? that's really boring and Porcelain Heart is too damn safe that bores (the acoustic interlude is really reminiscent to Vintersorg's Svältvinter intro). It has no atmosphere at all. Even GR had it - a awful one but at least had something. WS sounds even more fragmented than GR.
What I DONT get is how can be possible that people who likes progressive, doesnt like Vintersorg - at least since Visions.
note: I wrote this really fast