I've got a Manfrotto 190CXPRO4 right now, and I like it a lot. I found a crazy deal on it, though -- if I hadn't, the price on the Vanguards is pretty attractive. I've personally had a great experience with Dolica as a "budget" brand, and I've heard good things about
Adorama's house brand (Flashpoint).
As far as features, I'd start with the leg locks -- flip locks vs. twist locks can be sort of a Canon vs. Nikon issue for some people. I personally like flip locks better (having tried an Induro with twist locks), but I'd highly recommend you figure out for yourself which one you like, because that's the only answer that really matters.
Having owned both aluminum & CF tripods, I love CF, but it's one of the first things I'd give up if I had to save money somewhere. Other features are going to really depend on how you want to use the tripod, so give that some thought. For me, the horizontal swing arm on my Manfrotto is great, but I know there are also people who'd never use a feature like that. I wrote up a couple tripod reviews that might be helpful just in seeing features:
LambertPix » Budget tripod shootout, part 2
LambertPix » Budget tripod shootout, Part 3
Again, I'm not sure I'd recommend either of those tripods per-se vs. something like the Vanguard that was mentioned earlier, but the reviews might be helpful in looking at features.
Finally, you mentioned quick releases and portrait vs. landscape mode, and this brings up another point to look at. I started switching my stuff to ARCA-compatible clamps & plates maybe a year or so ago, which is nice as you start to accumulate stuff and/or share with folks (you can carry one tripod and share it with someone just by giving them a spare plate), but I also picked up an L plate for my camera last fall, and it's really nice for switching the camera from portrait to landscape -- rather than laying the head all the way over to switch, I just release and re-clamp the camera, which retains the full range of motion of the head, and also keeps a much better geometry if I want to shoot a panorama in portrait orientation. I mentioned that not because I'd encourage you to run out and get an L plate right away, but because if you get started with an ARCA-compatible quick release system now, you'll find stuff like that easier to add on later. There's probably a whole other discussion to be had around how compatible are "compatible" systems, really, but I'll spare you that for now.