Meant to follow up for any future searches...
Thanks for your input & replies!
Got the Elite cages, they are pretty snazzy. Hold the bottle well with a positive 'snick' on putting them in, and the design of two 'wings' means it is easy to get them in and out. Functionally, therefore, they are great.
Is it worth the extra cost? Well, they genuinely feel better than the £4 alu ones on my winter bike, but not 10x better. But they look way better, so for a vainglorious fool like me they're great!