FurAffinity
Pros: Mostly sane user base of various views and ideas, thumbnails don't get cropped, generally loads quickly due to Web 1.0 design.
Cons: Dragoneer, abysmal for written submissions, code is like Swiss cheese.

Weasel
Pros: Admins actually listen to their user base (which is actually rare for ANY website).
Cons: User base tends to have holier than thou attitude and is full of petulant Tumblr-types, site crops thumbnails by default, site layout is convoluted.

InkBunny
Pros: Changeable backgrounds, ability to put multiple images in one submission, very secure (or so I've heard), ability to rate favorites by precisely how much you like them.
Cons: Cub art.

I don't know enough about SoFurry to talk about its pros and cons easily, but I've herd it's the go-to site for writing. I don't know of cons aside from small user base.

He sums it up really damn good

DeviantART
Pros: Can change Username, Editable Main Account Page
Cons: Incredible childish User base, Ignorant Staff

I'm sure there's more to add here...

Also Cons: Hardcore porn is not allowed. Site is a actually too popular which makes it hard to get noticed. Way too much shitty MSPaint shit compared to decent art.

I don't know enough about Pixiv to really say anything about it.
And I didn't include Tumblr because it's a general social networking site, not specifically an art-hosting site.

I hate DA for that reason. Shit is spammed so much to where you art is on the front page for 2 milliseconds.

Pixiv:
Pros: porn is allowed
Cons: Different language, seems very non-personal. users dont seem to comment, art quality seems to be like that of DA

Isn't Tumblr a blogging site really, not a social networking one?

Yeah, but it's got a large artist community, so I sort of think it counts.

Inkbunny...i like the site, not how much cub art there is.

I kinda like sofurrys market place, nothing else really. The layout also feels.....like theres too much on the page?

weasyl's layout feels good imo, but I dont see the reason to have links twice - such as to browse, the forms, ect.

I also don't like that username links are weasyl｡com/~XXXXX which is kind of annoying to have to remember. At least on FA, it's simple. furaffinity｡net/user/XXXXX

And I heard that InkBunny is where all the cub artists went when FA banned the stuff. And as far as I know, it's the only furry site that still allows cub art.

Ideally, I think this is what would make a good furry art (and general art) site:
A search bar on every one of the webpages.
The ability to filter out art with certain tags.
Categories by Art Type, Rating, Genre/Fetish, Species, and Gender. (And gender should be more expansive, differentiating between women with both a penis and a vagina, women with just a penis, and men with a vagina, regarding popular third genders in the furry fandom.)
A simple rating system like that of FurAffinity: General (clean), Mature (genitals, mild gore, etc.), Adult (hardcore porn, extreme gore).
Folders to categorize types of art.
The ability to rate Favorites based on how much you like them.
The ability to post multiple images/text pages/audio in one submission, as well as to combine these forms of media in submissions.
Large thumbnails for previews, uncropped.
Buttons to share content on various social networking blogs, both furry and mainstream.
And most importantly, admins that actually give a damn about their user base.

So, just combined inkbunnys features and weasyls? If only :/

I don't like weasyl UI. It's why I tend to make FA my primary. Sf is my backup. The only negatives I can say are small user base and sometimes it can get clunky when submitting

LOL!!!

I like Weasyl's layout more, and their stream setting is such a cool feature (as is the collection feature, but no one ever uses it properly..). However, it's so freaking dead there. :/ It takes too much effort to force my followers to that website, so I update it, but without much effort. Maybe in 10 years, I'll have half as many watchers there that I do here! If it were a more active site, I'd probably switch. Not as it is though.

yeah, one thing I have noticed about weasyl is that its hard to find via google compared to the other 3 furry sites.

Before I came to FA I used to watch artist on TeamArtail.

FA is the least-advanced and feature-poorest of the 4 major furry art sites... but the value of a social network really isn't the technology and features, but rather the users and the content that they provide.

And FA is by-far the largest and most user-generated content. Maybe FA does deserve all these users, maybe they don't... but it is true. So FA is my favorite furry art site and the reason is because it has the most users and most content.

After all: you could have a PERFECT furry art site that does everything you want perfectly... but what good is it if nobody uses it? Its the other people and their media that give the network value.

Sad but true. Same reason as to why I use FA so much.