Gotta say, I'm finding Hearthfire a lot of fun! More than I expected I would, at any rate. I figured it'd be a nifty "build a better house" addon. But then, y'know, I adopted a couple kids, I got married, I got a horse and a dog and a Steward, and suddenly I've got a pretty awesome base of operations where I store two powerful followers, a horse that doesn't just up and bloody vanish on me, an animal companion, and a constant source of supplies. Plus my house just looks cool.
I do wish there was a little more modification available. Picking different styles of plates and goblets, or different colour schemes. And Bethesda has their wierd fascination with putting sacks and barrels everywhere, which I just don't understand. This is my house, I have a whole goddamn cellar and I have a kitchen and I see no point in this pile of storage crap in the corner of the dining room, it just looks stupid sitting there. Plus, it's irritating that I can't have, say, a Greenhouse AND room for the kids, or an armoury AND a library. Yeah, I know I can just buy two houses, but the whole point of having one big mansion is that I can do all that stuff in one place. The cellaris really pretty pointless once you have the full smithing setup in at least one other room as well as outside the house. The Alchemy and Enchanting towers are equally unnecessary since you already get the two crafting tables in the main hall, so why do you need to double up? The storage space in the North Wing is even more pointless, considering the house must have about forty containers by the time you're done. You do not need another entire wing dedicated to storing crap in.
I'd also have liked to be able to keep more than one companion at your house if you don't have a familiy. I can set the place up to have four single beds and two double beds, surely I could get a little band of followers to crash at my house. Even if I can only have one follower at a time, it'd be awesome to come home to my Mead Hall and have a half-dozen hearty warriors there to greet me. That sort of roleplaying is the whole point of Hearthfire after all, so it sort of seems odd that I can't do it.
That all said, though, I'm glad I have this addon. It's definitely a good addition to Skyrim, even if I feel it misses a few opportunities to be a GREAT addition.