Map looks good.
As for the poll, I find that all four traits are extremely important. A map that comes across badly artistically can fail to inspire the imagination. If it doesn't look good, then that sets up a psychological dislike for the map (or any piece of art), and thus less chance that I would bother trying to like it enough to study it to see if I would use it in a game. Now, this doesn't mean that it has to be tricked out with jewels, fancy borders, and a perfectly-shaded parchement-replica background. A map that is just a black and white grid, if done cleanly, can be just as useful and inspiring. Take for example, the maps of Phineas Crow on these boards; they are not decked out with lots of artistic or thematic elements, but are spectacular in their ability to be used in a game.
Utility factor is extremely important, as well. Conforming to a 5- or 10-foot grid may not be a natural, organic, expected way for a building to be constructed, but this isn't the real world. It's Dungeons & Dragons, a game that involves a lot of tactical combat in the age-old heritage of "killing stuff and taking the loot." Fudging reality a few feet here and there is almost always perfectly acceptable in order to make the map more useful. Combat-grid portability plays a role here, too. If there's a chance that combat, another type of encounter, or anything else where tactical movement may come into play exists, then being able to pinpoint your location becomes extremely important (to those of us who use minatures and battlegrids, that is).
Level of detail depends on what's being described. If a feature is important (columns, the evil altar, key pieces of scenerey or props), it should be placed on the map. Maps that are an overview (like the one linked above) don't necessarily need every tapestry, candelabra, and soot-mark painstakingly detailed; showing the features of interest (evil face, fire-trap, the pews [which are of tactical importance due to cover and movement restrictions]) is all the detail necessary. If you were instead mapping a house that is 20'x40', then more detail would be called for: furniture, storage containers, cabinets and shelves, and more of the minutae that may be necessary to keep track of in such a small location.
All of this is from a DM's perspective. Player handouts and props need not have such a utility-factor. If the characters encounter a treasure map, and you give the players a copy of it, then a simple charcoal-on-parchment sketch would suffice; the characters wouldn't be interested in a battle-grid. In this case, only artistry matters in the options above. Make it look like it was created. Adventurer's map? Should be sketchy, maybe drawn in parts with arrows linking areas that would extend off the edge of the page. A professionally-drawn strategic map used in a warroom should have lots of detail about terrain, elevation, and land- and water-based transit routes.
Short version:
DM's: Utility
PC's: Shiny
I love the ToH map, by the way. The only way it could be better is if it had a bare-bones b/w version to accompany it to make it easier on ink consumption.
