Yep - I've made it, as has my cousin.
I think it's okay, but my cousin raves about it, and reckons it's the best vindaloo he's ever made. In fact it's become his default vindaloo recipe.
This highlights how personal tastes come so strongly into play in this BIR lark we enjoy so much.
For me, at vindaloo heat levels I personally couldn't discern any additional benefit from the use of cardamom powder, which is quite a subtle flavour (unless you use too much!) and gets lost amongst the chilli heat.
I love my garlic and ginger, but don't think the second helping of garlic and ginger just at the end is a brilliant idea (unless you like the taste of barely cooked garlic/ginger, and don't plan on breathing near anyone any time soon!).
I'd much rather use more at the beginning (which is what I tend to do anyway with hotter curries).
But as said, this is just my personal take. Do give it a go to spec and let us know what you reckon.