I take delivery of a Canon 500mm f4L II this week and have researched the hell out of gimbals for large lenses. Here's what I ordered and my experience in researching and even almost buying one on Gumtree where the seller tried to rort $130 for an Aust Post satchel. LOL. In a nutshell, the Wimberley is not the lightest. There are others with a weight saving of 600g to 1.6Kg. That's a lot when it's all literally, on your shoulder. However, Wimberley WH-200 is the standout best for me because I've not been able to find any complaints about it performance- or fault-wise compared to most of the other brands and the reviews all say that other brands are modelled on the Wimberely. But you're paying for it. I ordered mine on the weekend from B&H. I ordered from B&H (all in stock): Wimberley WH-200 Gimbal Tripod Head II with Quick Release Base USD$594.50 Wimberley P40 Quick Release Plate USD$58.00 Oben 3/8"-16 to 1/4"-20 Reducer Bushing USD$2.49 <-- this is needed because one of the holes in the 500/4 foot is large so it needs to be reduced to use the plate. Shipping DHL 5-7 bus days (their prices are really good) USD$31.86 Total USD $687.25 = AUD$881.00 on my credit card. You can get it in AU. I chose not to. B&H, of course, is cheaper. But one of the companies in AU selling the Wimberley was never going to get an order from me ever again. A previous experience saw me getting my bank and Dept Fair Trading involved some time ago. Nuff said. Then there's another who's prices are waaay higher than B&H and then there's another with prices that are questionable compared to B&H and so on. Then there's one for sale on Gumtree. Right now. It was advertised for $600.00. A steal. I spoke with the guy. Asked for near a week for pics. The emails, texts and phone calls kept sounding alerts to me. I cautiously agreed to take it. Asked for postage price. For a 2.8Kg package via Aust Post Satchel (worth $29 with insurance) he said it was $130 on top of the $600 asking price. Told him to piss off. The alternate to the Wimberley WH-200 is their WH-200S "sidemount" which is popular but you mount the foot on the side (sideways). The WH-200 is better for balancing your setup and there are comments from people that they wouldn't use the WH-200S Sidemount version with anything heavier than a 500/4 (3.12Kg). No idea why. Perhaps it's that mounting sideways instead of with gravity is more of a pain. I made notes of the pros and cons of everything I looked at. I don't have them in front of me, but most follow a similar theme: Firstly, weight handling. Many were rated for 10-15Kg. That should, theoretically, be good enough for your or my setup. But I also consider that I might lean on it or worse, accidentally belt the gimbal accidentally when carrying it without the camera on it. So I prefer something tough. The WH-200 has an amazing weight rating that nothing else came close to. I think it was 26Kg but don't quote me on it. And it was the only one that would take the heaviest of lenses. Many other brands were barely rated for the 500/4. I remember looking hard at the Sirui as some love it - others, however, don't as it turns out. It's about $600 + a plate. It's pretty sexy, carbon fibre; it's lighter than the Wimberley and looked great. Except for one thing. The reviews and complaints I read all pointed at the pan mechanism being geared, in that when you lock it, it may seek a free tooth gap and move the lens - and your composition - a little. At 400, 500, 600mm, that's a big deal. There's a lot of complaints about that little oversight but I haven't been able to confirm if that was resolved in a more recent version. Other people said the pan or tilt or both were necessarily stiff; others said their copy was perfect. It's made in China and some are saying it's a QC problem. I gave it a miss but, to be honest, if the gearing problem was solved (it might be already) and I was able to test it with a lens mounted before buying, I'd give it another look because I've seen some of their other products and they actually look and feel nice. There was one brand, I don't recall the name, that looked promising and had a reasonable weight bearing capability but had, perhaps, the dumbest design I'd ever heard of. The Arca holder (in the arm) has a jaw that opens but not enough to allow you to drop the lens foot onto the holder, with Arca plate attached, then lock it - as you'd expect. This one has you opening the jaws and then sliding the foot/Arca plate in from one end. All with possibly one hand at times. Dumb, dumb, dumb. And to top it off, the moving side of the jaw was very short and there was an observation that it just didn't look very secure. To be fair, there were some brands I saw that looked good and would have done the job for me. But most were not far off the cost of the Wimberley and many weren't available from a big supplier like B&H so I'd really only be saving $100. And for $100, I'd rather the peace of mind for the lens investment. Oh, and the Mongoose. That looks great. But the optional arm assembly is out if stock everywhere. And that was the only other one I'd have considered. Same price as the Wimberley.