Hi, I don't have the Primus, but I have the MSR whisperlite international. I like it a lot. Info on the stove here:
http://www.msrcorp.com/stoves/whisper_intl.asp
It can burn white gas, butane, and unleaded. I have tried all three in the unit, and it works great. I have read some reviews on the JetBoil, and while people like the stove, you have to use the included pot, and you can not fill the pot all the way to the top because it is unstable. The other problem with the JetBoil is that you must use the canisters, and while you may be able to run over to Wallyworld or your other favorite retailer to get a refill can, in remote areas or internationally these may not be available. Hope this helps.