We are absolutely awful as a community, unless you get into one of the better progressed guilds on the server such as Convergence, Sunder, or Gimped.
They each have a good rep except for Sunder and Gimped.
Wait... where is Cata there? or my GUILD! :O
My guild is awesome! Is made up of bronies :D Friendship is Magic!
Did someone say... BRONIES?
But really, in terms of:
I'm looking for a server with a tight community that actually enjoys interacting with each other
I've found that KM Horde does better than most servers. This is partially because there's a low Horde population, so most older players know at least a good chunk of the players on Horde side. Off the top of my head, I can only think of maybe 2 Dbags on Horde on this server, and the one that comes to mind first is amusing enough where I don't feel like putting them on ignore.
Anyhow, in terms of pugging (which you mentioned), I haven't pugged in a while, but the pugs that I was in were generally well-natured (no HURR 365+ ilvl and achieve to do Reg T11 content). However, Horde rarely pugs anything besides BH, and most pugs seem to fall on their faces.
Which brings me to my next point. In terms of actual skill in the game, the vast majority of Horde players are, quite frankly, pretty bad (or I'm just elitist (despite being not amazing myself), I don't know). If you want to actually make progression in PvE on Horde side, you pretty much have two choices: Our guild and Ret (who, if I recall, is a sister guild of sorts in relation to our guild), since Horde is weak in terms of 10-man guilds (no offense). I can't speak for Ret, but we have a hell of a lot of fun in our raids, and even if we have an off night, we still stay well-knit (which explains why we've been around as long as the server itself, if I recall). If you can't get into either of those guilds (or you get kicked from either for whatever reason), you're pretty much SoL in terms of PvE. In terms of PvP, Horde is generally weak (although better person for person than Alliance, IMO). We don't have many serious arena teams, nor do we have many people who have hit 2200+. In addition, RBG groups are pretty rare here, much less successful ones (although we have a Hero of the Horde somehow). So if you really like PvP, this may not be the faction for you.
So that list of disclaimers aside, I'd like to reiterate that despite Horde players complaining about our community, we're really better off than many servers (particularly the high-end Horde-dominated servers, such as Illidan, Blackrock, and Mal'Ganis) when it comes to community. Of course, this is just personal opinion on my part.