I did quite a bit of research about this last year, and eventually I settled on a Manfrotto 190CXPRO4 carbon fiber tripod with a Manfrotto 496RC 2 compact ball head with quick release plates. ...
I chose the Manfrotto 190CXpro3 model legs ... the three section legs are a bit longer and a bit sturdier than the 4 section legs, and very slightly lighter. They don't pack down quite as small. I fit them with either an Acratech Ultimate Ball Head or Markins Q3 Emilié head, both very light and very precise. The heads cost more than the legs, but are worth the money. All up, the total package weighs three and a quarter pounds and is my go-to tripod setup for general use. With either head, about $450.
When I need more elevation or load capacity, I have set of Feisol CT-3442 Tournament legs. These are larger section, four segment legs with a large camera support yoke which can be fitted with either a flat mounting plate or an adjustable center column. I fit one of the same two heads to them. With adjustable center column and the Acratech head, they pack down into a light (supplied) carry bag that is 19" long, about 4.5" diameter, and weighs 4.2 lbs. Fully extended legs and fully collapsed center column, with head in place, nets a camera platform at just shy of 72", which is a couple of inches higher than my eye point when I'm standing next to them. The adjustable column and net another 10" upwards. These legs are a bit pricier: $400 for the basic legs, another $60 for the adjustable center column, so by the time you buy a good head you're up to around the $700-750 mark.
The Manfrotto legs are convenient, light, fast operating but a little short.
The Feisol legs are a bit slow operating, very very sturdy, have great elevation, and are very portable for their capabilities.
Advice: don't skimp on a head. I gave up on the Manfrotto heads due to the RC2 plates and clamps—they're simply not very precise. I standardized on heads that use the Arca-Swiss type quick release system of plates and clamps. EXTREMELY precise and solid, they never jiggle around as you lock the camera. And a high-end ball head is similarly very precise and secure. Legs need to be stiff and hold up well, they're pretty simple; heads you have to touch and manipulate constantly so the controls and precision are critical.
G