The key things to look for in a tripod IMHO are:
1-Weight capacity. The problem with all of the inexpensive pods is they are very weight limited. Get something you can grow into. To me anthing with a capacity of less than 4 KG (8.8 lbs) is a false savings. If you get serious about the hobby that's enough capacity to hold a digicam and an 80-200 2.8 or a medium format camera. That weight capacity will still give you a fairly light carry weight.
2-Interchangeable heads, for obvious reasons.
3-How high does the go without raising the center column. All the stability on Earth evaporates quickly when you start raising the center column. I have no hard empirical data but I would guess that camera shake is multiplied by at least a factor of 2 when the center post is fully extended.
4-How short will it collapse. I find this to be as important if not more imprtant than weight because it affects mobility on remote locations. The farther under 30" you get the better.
5-What does it weigh. I think people fixate on this too much. When I go in the woods with my backpack, 80-200mm, 300mm, 28-105mm, 16mm, camera body, and various widgets I'm probably at 30 lbs +/- already. Yes a 2 lb pod would be nice but it's very weight limited. A 6 lb pod won't make much real diffence to me, or aven a 10 lb pod for that matter.
My $0.02. YMMV.
LWW