Thank you! Though, I have to say, I did grind and probably over-leveled for the fight a bit :) Still, it was tough for psychological reasons, as I said.
Mechanically, I actually feel Maneater and Flame Lurker were a bit tougher, but I was also lower level so it could be that, too.
I think that Flame Lurker was more difficult for sure, partly because you face him so early in the game. Playing through the game blind, he's pretty much the third "real" boss you fight in the game (I don't count Phalanx, lol). By the time you get to Maneater and Allant, you've played many more hours of the game and you're just plain better at it in general. If you went back to Flame Lurker now, you'd probably make much shorter work of him.
For some reason, I never had much trouble with Maneater back in the day. My playstyle probably just meshed well with the fight.