[Aluminum] The foot that comes with the Sigma 150-600mm Sports lens made the lens-camera combo too front-heavy for it to balance on the gimbal head (Oben GH-30) when in the extended 600mm position.

When using this foot instead, it balances perfectly. (Annoying that I had to pay $100, but this is a well-made product at least.)

[Aluminum] I replaced the factory foot with this on my Sigma 150-600mm lens. It makes a good sturdy carrying handle for the lens. I was pleased I could mount it directly to my tripod with out having to add the additional mount.

[Aluminum] Had a great chat with customer service. Turns out I needed this part to make my new set up work. This is why I shop B&H. Thanks!

[0.6 lb] Although I can use the original foot on one of my older tripods, using an ancient Linhof pan/tilt head, these days Im in love with ARCA plates & clamps. It still surprises me that major lens manufacturers dont offer purchasers the option of an ARCA foot - maybe they arent chasing sales after all?
The Wimberley foot is easy to fit - the instructions are simple, clear and straightforward - it only took a few minutes and it was done. As solid as!
A  minor issue - once the foot was in place, it was slightly harder to park the car in the garage - I mean put the lens back in its case.  But not difficult, once you realise why.
There is also a Jobu one, which mimics the shape of both - longer, like the Wimberley one (which is an advantage, in balancing this lens, with camera) - but lower, like the one SIGMA fitted.
But its 20 bucks more and the extra height in the Wimberley one makes it easier to use this lens hand held, if you ever want to - birders, perhaps?
B&H advised me this one was the obvious choice.

[Aluminum] I purchased Wimberley replacement foot for my Sigma 150-600mm Sport Lens. The extended length of the foot helps balance the lens when fully extended in 600mm in my Wimberley WH-200 Gimbal Head VII.
It fit perfectly and was easy to install.

[Aluminum] I'm using this with a Sigma 150-600. With this foot I don't need an Arca type plate adapter to use my gimbal mount. One less connection to work loose. Also, I like the double dove-tail.