Yes they are that good, I would not be without mine, especially with the 500 f4, it makes light of using the lens.
I have tried a few, currently my favourite is the Jobu Blackwidow LW II, well made, works well and gives me the greatest range of up and down panning with the lens. Some models are quite restrictive in this regard, which makes following a bird in flight tricky.
There was another mentioned recently on here, which got some favourable comments, the Lensmaster, and half the price of the Jobu, HERE, I have not tried one but may be worth a look, as it is cheaper than the Chinese copies.
I didnt think of that- its going on a Sigma 150-500mm so I can move the mount on the lens to one side
Im up in Yorkshire this Friday & Saturday, Ive just e mailed Lensmaster to see if its possible to call and collect, so I could in fact have a hands on with both models- I work long hours away from home so delivery would be a problem for me
Ive just spoken with Rob ( who makes them) Im collecting an RH2 on Friday afternoon
Your welcome ... some people get worried about the side mounting as they fear they will drop the lens in the process of attaching it to the plate, the horizontal plate of the RH-2 offers more assurance in this regard.
The problem with the RH-2 is you cannot adjust the height of the plate, so actually getting the centre of gravity of the lens smack on is not possible, which can have an effect on achieving perfect balance with the set up.
With regard to side mounting I have been using this method for several years with a far heavier lens than your Sigma, and have not had any issues, you just need to work out a safe routine and stick to it, I always have both arms below the lens, to act as a cradle should it not engage the plate. I also only extend two sections of each tripod leg to start with, this keeps everything at a comfortable level for the procedure, once the lens is attached and secure I extend the third leg sections.
I bought a Lensmaster gimbal and after trying it out I decided it was not for me, the inability to raise the lens/body to be level with the axis of rotation was what put me off.
Having said that, the Lensmaster owner is a very decent fellow and refunded me even before I'd returned it. If that particular feature being absent doesn't bother you then it's fantastic value for money.
In the end I bought a Wimberley from Kerso. I decided not to skimp on support when there are thousands of pounds worth of precious gear balancing atop the tripod.
In order to get the centre line of the lens level with the pivot point you need to be able to raise and lower the platform that the lens is attached to. This is not an issue with the RH-1 as you are always have the centre line in the correct place due to it's design.
Here are a set of Wimberley instructions that show how to set up their gimbal LINK
How much of a problem this would actually cause in balancing the set up I do not know as I have never used a gimbal with this design, I have always used the side mounting type.
I have a Custom Brackets gimbal on loan ATM, and very nice it is too You can adjust the height of the lens to align the axis of course, but in practise it's okay (if not ideal) to use without aligning exactly, so long as you have hold of the camera.
The main purpose of axis alignment is when you let go of the camera, the whole rig stays balanced wherever you left it, even with all the pivots loose. If the lens is not axis aligned, there's a pendulum effect and the lens will swing down to the horizontal balance point.
I guess tightening up the friction locks a bit may kind of sort it, but my view is since these big lenses cost an arm and a leg, the tripod won't be cheap either, and a chain is only as strong as its weakest link. The whole point of a gimbal is to make the difficult job of holding a monster lens as easy as you can make it. I wouldn't skimp, and if budget is tight check out a Benro gimbal from DC's Store here (recommended ebay supplier) http://stores.ebay.co.uk/DCs-Photog...03156018&_sid=896782438&_trksid=p4634.c0.m322 The Benros are Wimberley clones, and the GH3 a copy of the Custom Brackets gimbal.