I think anyone investing in a tripod should try it out in person at a store or a show
Definitely try before you buy!
I started with a Manfrotto head on a Gitzo stills tripod, but quickly moved over to dedicated motion sticks. Lived with it for awhile, but eventually picked up a Satchler system.
In my case it was the FSB 8 head with SideLoad plates, & Speedlock CF sticks with 75mm bowl. The head is so much better than any Manfrotto I've used that it instantly made my operating smoother, while the SideLoad plates are identical to Manfrotto's 501 series, so can be used on either system, which was a consideration as I use Manfrotto heads for applications that are well suited to a flat mount, especially monopods.
But one thing to beware of with the Satchler is mine has a short mounting post that doesn't play well with many other manufacturers' bowls. I have two Hi Hats the Satchler won't fit, but they do offer a longer post that I've been meaning to order.
The SpeedLock sticks are great, & the 100mm versions are extremely popular with news crews, but are optimized for speed of operation, & don't go as low, or high, as many others. On paper the Carbon Fiber version doesn't seem that much lighter than the aluminum, but in usage it does, & more than paid for itself in reduced airline overages.
Sam mentioned a floor spreader which is a bit of kit I generally do not like. They're great on a flat surface like a studio floor, but on uneven terrain they're no where as useful as a mid-level spreader.
There are numerous great options available, & no one brand is best. If you have the time look into second hand options, but be sure to test drive. Generally the head is more important than the legs, but either can ruin a pan if they spring back at the end of a move, or aren't able to handle the load. Look for a system rated 30-50% heftier than your camera setup.
If your not using your Gitzo for stills anymore consider Jon's suggestion to add a bowl to it, & invest in a great head.