I just got the Hall of Fame last night. I like it alot, best reverb I've ever had, it's very transparent, doesn't color your tone. Matter of fact many times it's hard to tell it's on, you just notice your tone is alot more spacious (though I'm really trying it with the controls at 12:00). It has a very wide variety of reverbs as well, to go from Fender Spring to Hall and beyond. It's the first reverb with a Hall setting where I really felt I was in a concert hall, rather than sounding like an add on effect trying its best to emulate a hall but never getting quite there
It is much better for Metal tones than the EHX Holy Grail, but still, for Metal I prefer delay over reverb, if I'm going to use something for ambiance.