Yes, I LOVE Argis! (So much that I accidentally cloned him using the wrong console command, long story.)
....
I just imagined myself as the meat in an Argis sandwich. *faint*
Argis is the only housecarl I've ever had as a follower for any substantial length of time... I think my experiences with Lydia had just turned me off the idea completely. The one playthrough where I got all five housecarls plus the associated properties, I ended up sending three of the first four to the Blades just to get them out of my hair when I was at home and the one in Solitude I just left there because I so rarely used that house anyway (or at least the part that she hung out in). When I got the house in Markarth I think I took a shine to him because the VA was the same as Farkas IIRC, which tickled me. I was without a follower at the time and thought, okay, WTH, let's take him along.
I'm sure part of the reason was that I had leveled up considerably before I ever met him, but... yikes. He was just a TANK. I put him in ebony armor first and then some custom enchanted dragonplate with enchanted jewelry and ebony weapons as well and he was almost unstoppable. He once rushed ahead of me and killed an attacker with nothing but shield bashes. I'm pretty sure he one-shot a dragon once with his bow, his archery was just impeccable, to wit:
[img]http://img195.imageshack.us/img195/9716/iseeyoumetargis.jpg[/img]
I simply adored him. Becoming Thane in the Reach is now a top priority for my current character just so I can have him around again. I've already got a beautiful set of Dwarven armor and weapons ready to go as his starter set. (It says something that I have two other housecarls already, and even when I took them as followers, all I did was improve and add to the basic steel set they already had, and replace their crappy default bows with improved Imperial models. But Argis... he just has a special place in my heart.)
I prefer Vlindrel over most of the others simply because I prefer one-story player homes. (Proudspire is a beauty but those stairs drove me nuts.)
Eh, the look of Proudspire doesn't really appeal to me. I don't like Solitude in general but I dislike Markarth more, even so I still found Vlindrel Hall (even vanilla) more appealing than PM. And you're right, those stairs are a PITA.
Hjerim would be my first choice but it's the buggiest house in the game, especially since you have to do the buggiest quest in the game before you can get it. However, I am working on some Windhelm stuff now in the hopes of triggering Blood after the requisite visits and we'll see if I get better results this time around.
Believe it or not, I have done that quest 3 times with no problems. I must be the luckiest person alive.

Which Hjerim mod(s) do you use?
Currently using this one and loving it:
http://skyrim.nexusmods.com/downloads/file.php?id=9876
The Atronach Forge is a bit much IMO, but it's a separate cell accessible through a trap door so if I don't want to use it I can just pretend it's not there. Except for when I tell Erik the Slayer to "relax" and he goes missing, he goes down there and I have to go get him. I don't know what he finds so interesting down there, it's just a room with a magic forge in it and there's nothing for him to do. Unless he starts making me Daedric weapons, in which case, GO ERIK!

And I hope you'll give an update when you've seen the modded Vlindrel because I might try that also. (I'm stingy with certain types of mods and often only try those that people can explain WHY they like them - the comments on Nexus can be hard to navigate for useful impressions sometimes.) My characters all seem to love utilizing their homes, so it's an important part of the game for me.
The one I have right now is this:
http://skyrim.nexusmods.com/downloads/file.php?id=10339
Since I haven't been in the house yet, we'll just have to see. I've been through 3-4 Breezehome mods already with this character and may change again if the current one is too glitchy... usually I buy a house and go there first thing to inspect it, if I don't like what the mod does I just exit and find something else and then reload the save from before I bought the property and try again.