The Primus Omnifuel lets you burn liquid fuel and gas canister fuel, but, the Nova (which only burns liquid fuel) folds up smaller, and to me at least, seems to have a stronger build quality for around the same weight. I have an Omnifuel, but for whatever reason, the Nova steals it for me, plus, for a tenner, you can buy a kit and run the Nova burner in a pucker Trangia stove (25 or 27 model,(or the cheap Lidl stove sold recently). Really between the Nova and the Omnifuel, it would be down to the flip of a coin, unless you are like me, and have the sad hobby of collecting stoves, so choice in not an issue. Both stoves burn hot but would let you simmer a stew for a few hours not a problem
The MSR is a good stove, but reports from regular users/collectors tend to point to the fact that it needs more maintenance than the Swedish stoves and the pump is not the best quality
If I were you, I would go the Omnifuel or Nova route and forget the MSR, but this is just my opinion.
PS
You can pick up a new Nova from the states for about £65 including postage, if youre lucky you wont be hit for tax this end, but if you are, its probably still cheaper than UK suppliers prices
This guy sells the Brunton Nova all the time
http://cgi.ebay.co.uk/New-Brunton-O...ryZ16036QQssPageNameZWD2VQQrdZ1QQcmdZViewItem
Brunton is the American distributor for Optimus, so you get a proper Optimus Nova, just the box is marked Brunton Optimus, the stove is the real deal