I have The Jester Race on now. 
I tried In Flames around '00-'01, probably around Clayman, and there was no chance I was getting past those vocals.
This album is one of the ones, along with a couple from Soilwork and COB that made me fall in love with these types of vocals. It's incredible, I put it on and still get the same feeling of back then discovering this world of metal.
I don't listen to the debut or the EP all that much but should revisit. It's always been about the Jester Race for me.
Lunar Strain is ok, I'm fond of it, but don't love it. Subterranean, on the other hand, is all sorts of awesome. If you haven't listened in a while, please do yourself a favor and put it on. The guitarwork is so, so good. Stromblad and Ljungstrom are on fire. It really is a peculiarity in the band's discography, as they were clearly transitioning even in terms of line-up. They have Henke Forss on vocals (his only recording with the band) and Daniel Erlandsson + Anders Jivarp guesting on drums.
I agree The Jester Race is their best album, but the quality of the songs in this EP is just as good
Nick, just popped home for a quick coffee during work time and have pulled out the EP to take with me out in the car. I have the version with the bonus tracks too.

Funny, I can't find Lunar Strain, maybe I don't even own that on cd.......hmmm....that's weird. I'll report lack later on.