Honestly, i first found out about them a few years ago, and have heard everything through BBW, and thought it was ok, BBW definately being the best, but it is kinda repetitive, ESPECIALLY live, the sound was just really muddy, and the leads were kinda lost in the sound at times. And yeah, I was surprised to see a guy with that kind of body not wearing a shirt, but hey, I'm a bigger guy myself, so I can't really speak.
But back to the topic of the OP, the first time I actually heard HoF, was on the original Sounds of the Underground sampler thingy that has like, 10 bucks at hot topic. But anyway, Opeth was on that tour too, so I guess that's one time they've worked together.
Sadly, and this embarrassingly shows how much of an Opeth n00b I am, that was the first time I heard Opeth, cause they had Deliverance on there too. But hey, that was like what? 3 years ago? And considering I only started getting into metal about 6 months before that, I don't think it's that bad is it?