I do not have one. But have seen people using it and swearing by it. What is the minimum lens that one should have to be able to justify the purchase of this product. Can someone briefly highlight its use and advantages please.
It depends. Harris (Backdoctor) shoots his 300 f4 hand held and does fine. I can generally shoot actions shots with my 70-200VR OK, but my shaky hands make shooting anything with my 300 2.8 useless.
I have the Sidekick, and I wouldn't try to shoot anything that I really care about without it. In addition to greatly steadying your shots, it essentially renders the cam / lens combo 'weightless'. This greatly reduces fatigue on a long shoot.
If you have lenses of 300mm or greater in length, I would definitely recommend the Sidekick. Less than that depends on how steady your hands are.
I just bought one from a fellow Cafe' member and it works great. Like Frank said, your lens/camera becomes weightless. I use it with my 70-200 VR with the VR off and it's a great combo. I'm still lusting over a 300mm and consider the SideKick essential with the 300. FYI..with the 70-200 I did have to add an extended foot on the lens to get better balance with my D2X attached.
I really like the Sidekick. It is light and works just great. The problem that I had was that I got the wrong ballhead for my application. I got an Acratech Ultimate, and while it is a good, quality product, it doesn't clamp tightly enough (no matter how hard you twist the locking knob), so the Sidekick tends to 'creep' when I'm walking around the pond with it over my shoulder.
In addition, the jaws of the clamp that comes stock on the Ultimate are not very deep, so I've had the Sidekick (and my D2H + 300 2.8 ) come out of the clamp while carrying it. Talk about scary (I was lucky that it hit me on the head / shoulder, and I caught it before anything expensive hit the ground).
I warned Patrick about this, and he ordered his Acratech without the QR clamp, and put a RRS clamp on his. To my knowledge, he hasn't had this problem.
So, to make a long story longer oops, I felt like I needed to order a new ballhead. I was looking at the new RRS unit, but decided before ordering it that I would call Wimberley and ask about a rumor that I heard that they were going to come out with a new version of the full head. While I was talking to them, they said that if I was interested, they had a 2 month loaner program where I could try out the current full head, and return it if I didn't like it.
Well, I got the thing, and I love it. It is so easy to use, and I NEVER have to worry about anything falling off of anything (it is strong!!), so, I ended up keeping the blasted thing. I also kept my Sidekick, and I use it and the Acratech on my monopod.