i used to own the hs80m, and after demoing a lot of stuff i settled on the adam p11a.
the a7's were my favorite before going to the store and A/Bing them. well, they're good speakers, as others already said the mids are very forward and revealing, the stereo image and transient detail are great too. however, to me they seriously lack bottom end. sounds as if there's next to nothing going on under like 80hz. people tend to argue that they have an accurate amount of bass, but still, i think that in metal it's very important to get the low end right, and you can't do that if you're not hearing it clearly IMHO. that's why i'd always recommend a sub, adam sub7 or sub8 depending on your room size, when going for the A7.
however, adam a7 + sub is pretty much the same as the adam p11a, but you don't have to put up with calibrating and positioning the sub.
the p11a are VERY recommended imho. they share the forward mids, have a superb stereo image, depth, and transient detail, are very revealing yet not too fategueing, and go down to around 55hz i'd say. the adam s2x they had there were probably the best speakers i've ever heared (totally smoked the k+h o110), but that's a different league alltogether.
as for ermz arguement about the adams having unnatural mids, and the yamahas having a balanced sound...well....he's right, but at the same time he's wrong i'd say lol.
the adam's DO have a special sound to them. the mids around 2k are slightly emphasized, which makes the sound VERY analytical. at the same time, they translate wonderfully imho. pretty much the total opposite of genelecs...to me, the genelec 8040 had a dip around 2k, and coupled with the fat low end they instantly sounded nicer than the material actually was. i felt that i could do informed mixing decisions easier on any adam monitor than on any genelec monitor [the genelecs had the BEST stereo image short of the adam s2x btw, it was really amazing....just a sidenote]
finally, as for the hs80m: first things first, they are GREAT for the money. you'll be hard pressed to find anything better in the sub 1k range (i know, i was
). their frequency response is quite flat, however i felt the highs were slightly hyped, making them a more fategueing speaker than the adams. there was also a weird hole around 400hz, i just couldn't properly judge what i was doing down there EQ wise. they go down very deep btw, around 50hz i'd say, and stay punchy all the way. great speakers to impress clients
what i DIDN'T like about the hs80m is the lack of detail, be it transients, stereo image, depth, whatever. i found the stereo image to be quite smeared, with the hyped highend covering up a lot of the ambience information. it was also pretty hard to really hear what the compression is doing to the sound. it's possible to adjust and find workarounds for most of these points, but it's a pita imho.
overall, the yamahas are pretty impressive sounding when you first hear them, the sound is massive. however, i found it to be difficult to mix on them. the adams sound more boring in comparison, but they're not trying to hide the faults of the mix, like i felt the yammies did.
just my .02$ though