Hi Dylan, my experience to date.
2 x Wimberley 11 units
1 x RRS Pano
1 Jobu II
I've used the Wimberley units for several years, before that the version i units, can't fault them, they just keep working, smoothly & without fuss.
I bought the RRS Pano as I felt it would be a great replacement for the Wimberleys, and in some situations it is, on a Tripod, where you want to do Pano work etc, very smooth (better than the Wimberley), but I found in a vehicle (Safari) the Pano tends to load the weight to the side so vibration of the vehicle ensures the Pano head keeps slipping of vertical, not huge, but I've since gone back to the Wimberley units for Safari, RRS Pano for everything else.
I bought the Jobu as a lighter weight alternative to the above two heads, does the job, but I don't think it's in same Build quality area as either the Wimberley and certainly not the RRS, but it's cheaper, by a lot, tends to sit in the cupboard these days.