Opeth's Heritage album don't have any growling/screaming, just clean vocals...and I don't think you can call that singing "choir boy vocals"
That doesn't make one a music snob. But you do seem awfully picky. I don't know if you'd like Opeth's Heritage, cause it's more progressive rock than metal. You'd probably have to be into the 70s rock sound a bit. Not sure what I would recommend to you based on just the fact that you love Symphony X and hate Dream Theater, has to be metal but not growling nor "choir boy vocals". Probably nothing I like.
I haven't even listened to a single second of "Heritage", but I'd imagine that you would not enjoy it, Sister. As for Pain of Salvation, the entire Road Salt album (which contains "Sisters") is not really indicative of what they sound like as a whole, but I still feel that you would dislike them, regardless. Check out Leprous's new album "Bilateral". It's pretty metal in all the good ways, and just good song-writing overall. EDIT: Now that I think about it, "Heritage" and "Damnation" are not really indicative of what Opeth sound like either.
there is one part on track 3 that is "borrowed" from Warrel Dane's solo album. It is the heavy keyboard part
Based on your preferences I would maybe recommend you check out Evergrey if you haven't already, especially the albums "Recreation Day" and their newest "Glorious Collision". The vocals aren't the most elite or skillfull; however, I think they are much better than Labries', and at least have emotion. I used to hate growling style vocals back when I first got into metal; however, I slowly began to accept and even appreciate them. It wasn't like I just suddenly liked them out of nowhere either. I would discover bands where I really liked the music, but they would have growling vocals. I would listen to those bands for the awesome music and overtime I really started to notice the emotion they brought to the music. I began to see them as just another instrument to add flavor to the music, and realized how different those songs (the songs with awesome music but vocals I didn't like at first) would be without them. Anyway, long story short is that you enjoying that Blackguard performance kind of shows that maybe you are also on that path to eventually appreciating harsher vocal styles as well. The difference between clean and harsh vocals is really no different than that of a keyboard to a guitar.
Oh, and I meant to post this for you because I know it makes it more convenient for checking out stuff that is suggested.
Recreation day is a great album. Unfortunately their last three albums (MMA, Torn and GC) all sound the same...
Well said. Although both keys and guitar have actual notable pitch, and growling does not, I still agree with what you've said. Growls are another form of musical expression, and when used properly, are very enjoyable.
