The Paddock is bar with lots of rich dark woods and leathers in the decor. Despite the old-boy's club decor, the crowd is a yuppy late-20s, early-30s crowd and the vibe is pretty laid back. It's a great place to chat, since the music is set at a low(er) volume than in other bars and it's not ridiculously crowded. The drinks are pretty good with a number of decent/respectable wines, premium beers on tap and in bottles, and a good list of mixed drinks (including martinis).
The waitstaff are not overly chatty but they are courteous and efficient with the drinks list, the drinks, and the bill.
This place is a great place to take a date after a show at the Theatre Passe Muraille. The decor and lighting can pass as romantic without being cheesy. Plus, the relative quiet makes it great for chatting and finding out about each other.
I would also recommend this place if you are catching up with old friends and are looking to grab some drinks and wax philosophical.
I WOULDN'T recommend this place if you're looking to 'pick-up'. Not that the people there aren't attractive, but more for the fact that the vibe of the place isn't really conducive to that. People who go there generally show up in couples or groups, and they seem pretty caught up in whatever discussions are floating amongst them and the people they're with.
Hope that helps.