The pano clamp was another interesting point as I was lead to believe it wasn’t needed on the flex line because of the balance/tension spring. I got the pano clamp because of this reason on the uniqball. I have the pano clamp permanently fixed to my uniqball. I find it very useful, especially swapping between lens tripod foot mounted and camera L bracket mounted lenses. It has to be said the pano clamp does make things weigh a little more, the clamp adds about 150-200g (estimated as I don’t have any scales at present!!). For clarity it feels like that weight penalty should be added to the review as it takes it closer to the RRS head mentioned in the review. It’s not much but with it the flex line isn’t 680g any more.
.... It has already been about 5 months since I bought my FlexLine (they are now called 'FlexShooter' but I have no idea why the name changed) and I have used it a lot, mostly with Canon EF 500mm F/4L II and EF 100-400mm L II with and without either 1.4x or 2x Extenders. I now have two or three strong criticisms of the Flexline which are as follows :
1) - I have published this criticism before and it remains an issue which has become less and less acceptable to my way of working. It is that the Flexline's Arca-Swiss clamp is both very awkward to slip a lensfoot into due to having only four short corner clamp points and, much worse, the knob is a Slooow-Release rather than a Quick-Release < So that's two criticisms already. Without going into long descriptions why, I do quite often need to shoot to and fro from handheld to tripod, especially with the 100-400mm lens and so for me I have an issue.
2) - Once a lens is mounted on the Flexline's clamp it can become very tricky to see the rather small (too small in my opinion) bubble far below in the base ball for levelling. This becomes even more difficult when in a cramped hide with little headroom and in very low light - Something I discovered before dawn in Bulgaria recently.
A pano clamp such as Really Right Stuff's (RRS) PC-LR: Round Lever-Release Panning Clamp instantly solves both of my issues. Once I have sync'd and tightened the RRS to the flat levelled FlexShooter ball I can then use the far easier to see bubble on the top of the RRS clamp instead. And, of course, RRS release levers are among the very best and have a half-closed position enabling you to safely adjust front-to-back weight balance. The A-S profile clamp is also full length instead of four fiddly corners.
http://www.reallyrightstuff.com/PC-LR-Round-lever-release-panning-clamp
Nothing from RRS is cheap but their products are very high quality in manufacture and extremely well thought out in their design. They are a brand you can rely on.
The RRS PC clamp adds 336g to the FlexLine's 680g and just under 1.5 inches height but in practice in the real world this is simply not what I found to be a problem - It all still fits my tripod bag for travel and the weight is negligable. As well as having an Arca-Swiss dovetail on the underside, it also has a female standard size centre socket for other applications. A compact neoprene bag is also supplied.
An added bonus when adding the RRS, apart from extra panning options, is that without losing your precise level setup, you can swivel the RRS panning circle so that one of your tripod legs can be orientated forwards in line with your lens and you then don't have a tripod leg in your groin to contend with as well as better weight distribution and stability.
So as well as greatly improving the FlexLine/FlexShooter, the RRS Panning Clamp is a very usefull addition to your camera gear. What's not to like? Possibly the price but I say "She's worth it"
It so happens that I very recently spent 5 days with professional Guy Edwardes, who wrote the earlier posted review, but although I was literally sat beside him in a hide I didn't notice he had an RRS Panning Clamp on his FlexLine but with screw knob release rather than lever. Since getting back to the UK I contacted him saying hey I think I can solve my Flexline problems with a RRS PC to which he replied he was already using one and did I want to borrow it to try before buying. It's even in his review I read but he hadn't described the issues I was experiencing and so I missed it as the solution until finding it independently.
FlexShooter tell me that they are going to resolve the issues I have identified but as it's now at least 4 months later I am not holding my breath. I'll report here if/when they do.