In reply to Denni:
Hey Den, how's it going fella? hope all is well with you and the family.
I've owned both, and I reckoned the generator alpine offered the same amount of warmth, but felt a bit more substantial that the atom sv. The rab sizing was also a bit more generous. I reckon I've tried just about every synthetic jacket out there, and to be fair, there's not too much between most of them. It comes down to fit, colour and preference. As it happens, I sold my atom sv and got an absolute bargain on a Patagonia das parka, the only problem being that it's too bloody warm for all but the coldest weather- I was sweating wearing it in minus 12 windchill temps last week! I'm tempted to try the nano air as a less extreme, everyday synthetic jacket. There was also a Lowe alpine jacket which looked pretty good, although the name escapes me at the moment.
Finally, take a wee look at sport pursuit- they've got a fair few options in their outdoor jacket section at the moment.
Cheers,
G