In reply to JJL:
Like you, I thought the original Generator was absolutely the business. I guess not surprisingly, I've tried out quite a lot of the different variants available these days (the privilege of being with Rab!) that are as close as possible to the original and I've come to the conclusion of:
1. If you have to get same (it's actually a bit warmer) then go for Photon. But yes, it costs more
2. If you want the same kind of performance (but slightly less warm) then the new Strata Hoodie is a beast. I've absolutely hammered the ones I have had on cold, wet, big walls, trad, out on hills etc etc.
I've tried all the other jackets out, which are great, but those two make me feel the closest to that original Alpine Generator feeling.
Hope that helps.