Has anyone played this? Do you think a 'meatier' bulkier instrument facilitates the sonorities or is it better played on a lighter instrument for ease of execution (like a Broadwood maybe)?

It should sound good on any decent piano

A good pianist can play well on any piano! (Just an over-generalisation of course. Obviously the piano must be tuned )

Not sure if I agree with that. Richness in the bass and clarity in the treble are important in terms of the aural feedback that you get when you're playing. It's like having a good accompanist as an instrumentalist; if what you hear sounds good, then the performance will continue to thrive. But a weak bass, for example, can have the aural effect of making you want to compromise the balance of the hands. I think if you want a truly good performance, you need a truly good instrument!

(Or maybe I'm just not a good pianist... )

I'm afraid I can't answer specifically as I'm not familiar with this piece - but I always prefer a "meatier, bulkier one"!!

Yeah that was my point. If you're playing something like this you definitely need a heavier instrument though the point that a good pianist can play on any instrument is fair enough.