Hi folks. 

Has anyone tried the above?

I've heard plenty about the aluminium one & also that many have bent / deformed over time.

Thought I'd try one made of tougher stuff

I believe there is a big thread about it on here somewhere. 
 

there are 2 slightly different variants for the different mount types.

 

general consensus is they make it a bit rough to start with then settle down and have a much more positive feel.

Yes, so I'd gathered from other (mostly Mk7 golf forums).  

I've got a petrol model & so I'd expect less clatter at low revs than a derv with one mounted.

Definitely leaning towards the steel one for all the extra they seem to cost