Does anyone use him in your default group? How are his abilities and does he put out decent dps?

Honestly I don't think I had him once I got 3 characters to replace him.

Nope. As soon as I got enough party members to replace the dog, he was gone.

I'm not a fan of the dog. Sure, it has some neat abilities (like an AoE stun) and is decent at DPS, but it will be out tanked by Alistair and Shale and out damaged by Sten and Oghren (hell, maybe even Zevran).  Plus, it doesn't exactly have much to say about your situation, which is where a lot of the best party member dialogue comes from. So no, don't use the dog.

Nope, but he is a good tank, I believe.

Kept him.  He was pretty funny sometimes.

I have kept him so far, hes pretty cute and looks badass with war paint on

I would never get rid of Meatbag.

I love my Poops, best dog ever.

i had sex with the dog

He's ok. I liked his howl ability that stunned everyone around him.

I'll probably use him if I ever play through the game again. Reading up on some of his abilities, I realized he's not all that horrible a fighter. He's sort of like Shale in the way that he has a bunch of cool unique abilities, only he's far less useful and versatile. If you're playing to get the most powerful party members, I'd see no reason to use the dog. If you're playing for the role-playing and banter, it's still kind of iffy. He does have his own interjections, I've heard, and you can use him to find some lesser nifty items, but because he's a dog, what he has to "say" doesn't seem like it would be nearly as entertaining as any of the other characters. Although, considering I've pretty much heard what the whole rest of the roster of characters has to say, I'd probably take him for another run-through.

I only used him in one of the endgame sequences.  Not a great fighter (or maybe I wasn't used to him) but he did have some funny dialog sequences.

You mean my dog Kratos? Of course, its the ony SOB that likes me.

He was a no go because lack of dialogue.. come on, that's the fun part in DA:O :) Why should I have a non talking NPC in my party

My girlfriend refuses to play without the dog (Hamburger) and she seems to be pretty successful. @AndrewB: got it right in that, while you'd never place him on a top-tier team, his unique abilities make him a fun member to fool around with.

I can't fight the Darkspawn without Barkspawn by my side.

" i had sex with the dog "

" He was a no go because lack of dialogue.. come on, that's the fun part in DA:O :) Why should I have a non talking NPC in my party "

I kept him for awhile, until I got Wynne anyway, after that I needed a more flexible tank (Alistair) + mage (morrigan) + healer (wynne) and that was my party.

I kept him. Sent him in first to take them down by the neck.

It's funny. I hardly use the dog (Dogmeat) but he has the highest strength stat of anyone w/ me (even more than sten). if i leveled up his endurance, i think he'd make a fine tank.

He gets Overwhelm, but his skills are pretty boring.

He's handy to have in Lothering since you can swap party members on the fly and can do side quests without Morrigan getting bitchy.

" I kept him for awhile, until I got Wynne anyway, after that I needed a more flexible tank (Alistair) + mage (morrigan) + healer (wynne) and that was my party. "

He's good in certain occasions for instance one of his moves tackles an enemy to the ground and shreds him for like 4 seconds. This is excellent crowd control on a mage not to mention if he doesn't one shot him. Just pump all of his points into strength and you have a serious dps machine.

I only ever kept Woofenstein in my party when I was going to perform actions that would damage my relationship with someone that I was trying to sleep with (Lelianna in particular).  Once that was over, I'd put him back in the kennel.

I made an executive decision with myself to keep Fenris in me party for my first playthrough. He and Alistair make a decent tank duo.

I used him the first time I got him to see what he's like.  Replaced him afterwards.

I think the Dragon Age dog is easily the best dog I've seen in a game.  It's got more personality than most shooters.  Shame it's not a great character, I like the ability where he pounces a guy and then mauls him, I forget the name.  I kept him until I found Shale, I love Shale.

Like others have said, I like the banter between characters. The dog (Python), though he has some, doesn't have enough to warrant me keeping him in my party.

Dude, I don't go anywhere without her! It's a proper mage-killer, plus in the end, well, it's my dog, man. As a rogue (on nightmare) I play with me, my dog, shale/alistair and morrigan. No real trouble sofar, I'm about halfway through.

Played with him for about half the game once. Takes forever to learn skills with him but, at least the way I leveled him, he was always the last "man" standing in a tough fight. And like someone else said, the Overrun ability it awesome.

I take Ozzy with me many places.  He hates elves which turns out to be funny.

he is actually one of the strongest tanks in the game if you keep him.

I wish I could kick the dog out of my camp.
Any time I'm trying to listen to a party-member's story, he'll just bark & I miss key information.
 
Bioware games have such great characters & stories. With so many other interesting characters, I don't understand why anybody would take the dog.

I used him some, his ability to search an area for items has actually yielded some unique weapons, like a Bad A$$ mages staff. 

He seems stronger then my other party members, but I'm still at the beginning of the game.

" Nope. As soon as I got enough party members to replace the dog, he was gone. "

he might be good on later playthroughs, but the first couple just no 
 
i gotta be able to here my party members speak, it's one of the many awesome things about bioware games 
 
i usually get enough of my dog at the camp site, so really no reason to have him in the party

He isn't a regular for me; I don't even really like his design, but he does serve a purpose when you want to game your characters' approval.  Want to do something douchey that less than three companions will like?  Dog won't complain.

" i had sex with the dog "

Just discovered this mod: 
 
http://www.dragonagenexus.com/downloads/file.php?id=664

I didn't use him in my main party much, but I sure did enjoy stroking my little friend, Prickjuice.

I kept him the whole game. Between his howl which stuns nearby enemies and his overwhelm move, he was great in a fight. Not to mention he's tough as nails. A good tip is to set up one of his tactic slots to use overwhelm on enemies elite (yellow?) and up. Sometimes, I'd get in a fight and wonder where he was, only to find him pinning down and tearing the throat out of a mage. Good boy. :)

The dog makes up for the lack of commentary with little events he triggers.  Ever notice how almost every dungeon has a landmark?  Bring your dog to them.