[QUOTE=tdn]
Oh hell yeah! It’s the only RPG that I’ll play.
If you are familiar with the product line, then you are familiar with the name John Sgammato. He’s pretty much the lead writer these days. I play in his game.
[/QUOTE]
Sorry, but I am not very familiar with the line. 
I bought a bunch of Harn stuff in the late 80’s, while browsing through a local game store. (Game Town in Old Town, San Diego.)
The map packs were bee-you-tee-full. High quality. (And I see that the quality is still there in the latest products.) They caught my eye, sitting there on the shelf.
I bought a bunch of map packs, including one that included maps of the bigger castles & keeps.
I also bought the Harn RPG ruleset a short time after that, based on the quality of the maps. (I don’t think it was HarnMaster…) But the rules were somewhat different from the AD&D set that I was used to, and I had difficulty staying motivated enough to stick with them. (At the time, there were no published adventure packs.) Seeings how no one I knew was using that ruleset, I shelved 'em. (Still got 'em, in a box somewhere in my closet.)
I do remember seeing a sample of the bestiary in the basic RPG rulebook, and that the classic Orcs were renamed something else (Gargun?), but I don’t recall seeing much other fantastical critters. (There may be. I just don’t recall them.) Dwarves and Elves had a very small presence.
If my memory is somewhat close, then I would now venture to guess that the Harn world was intended to be more “reality” based, perhaps centering around medieval intrigue and power struggles. In other words, closer to real life than Tolkien style settings.
I ended up using the maps in an AD&D campaign I ran once. Heh.