The Bottom Line: The WhisperLite is a superbly versatile stove for the all-around adventurer looking for all season performance and the ability to switch to the convenance of canister stoves. While it is tricky to simmer with, the ease of maintenance ensures that it will last you a very very long time.
This stove has been tested on ski traverses, rustic hut trips, group backpacking trips, winter camping trips, mountaineering trips, and a canoe trip. It has endured rain, mist, powerful 30 km/h winds, and it has been used at -28 Celsius in the Rockies at 1,800 meters. The highest it’s been used is 2,500 meters. I mostly use this stove with white gas and isobutane canisters. I haven't tried kerosene, and I've only used unleaded gas for the purpose of this review (I would not recommend it).
The WhisperLite Universal is an evolution of the beloved MSR WhisperLite. When I worked in retail, I once had a couple come in a buy a WhisperLite for friends getting married because they wanted something that would represent longevity. I myself have done repairs on a 20-year-old WhisperLite that was back up and running after minimal work. The Universal is mechanically the same as the classic, though the wire pot arms have been replaced by sturdier stainless steel rigid arms. There are two other changes. First, it now comes with three brass jets: one for kerosene, one for white gas, and one for canister. Second, the flex tube also now takes a plastic nozzle, allowing the user to affix an isobutane canister (isobutane canisters are all the same attachment, so no need to worry about compatible canisters).
One great thing about this stove is that all these little parts have a built-in storage compartment in the standard bag. Basically, the WhisperLite Universal is the same old WhisperLite, but now you can use any type of fuel. Practically speaking, this makes it the most versatile liquid fuel stove, and it is on the lighter end of the liquid fuel stove spectrum.
I find liquid fuel stoves to be not worth the effort and not especially fuel efficient when being used for two people in summer. In winter, when you need to melt snow, that extra power and efficiency does go a long way. The advantage of the WhisperLite Universal is that you can swap it to a canister stove in the field to get faster and more efficient start-ups. The stove comes with a plastic stand for the canisters, so you can flip it upside down. This really helps the stove work better in cold temperatures, and it ensures any liquefied gas is still usable by the stove.
In liquid fuel mode with stainless steel pots, I found the stove simmered poorly. You can try a trick where you only slightly pump the stove to minimize pressure, but I still find that the WhisperLite isn’t nearly as delicate as the MSR Dragonfly. In canister mode, it does seem to simmer better if the can is facing up. This helps the stove's efficiency, as well. As a boiling and snow melting platform, it’s okay. It lacks the kick of the XGK or the Primus Omnifuel, but it’s really only a little behind when melting huge quantities of snow. With that said, it still does this job well, and it is on par with most liquid fuel stoves. In my experience, for two people, a standard 650 milliliter bottle lasts three and a half days with some to spare. You can find a good graph and fuel consumption chart on MSR Blog.
One big advantage to the Whisperlite is that it packs down to a very small size. When wrapped up properly it can fit inside most 2.5-liter pots with room to spare for cooking utensils and other items. I can normally just barely cram my GSI Crescent Cook Kit and the stove into the MSR Alpine 2 pot set.
I have used gas in this stove as a experiment. It definitely didn't perform nearly as well, and it left an odor. I think this is more a fault of the fuel type. Living on the Pacific Rim, I like the idea of having a stove that can use any fuel type when the "Big One" hits and we may be without easy access to fancy fuel types for awhile. So it's nice to know this works, though I think frequent cleanings would be necessary.
The Primus Omnifuel stove offers slightly better heat output, better simmering, and is approximately the same weight (don't trust the online specs because they omit the fuel pump). Why buy the WhisperLite then? Maintenance. The Omnifuel is simple, but it is also cast in a way that makes disassembly a challenge. WhisperLites can easily be totally disassembled, cleaned, and restored by hand. MSR WhisperLite Annual Service Kits are cheap and easy to find, making quick work. They come with great explanations, and there are a plethora of helpful and simple YouTube videos to go along with this. The Expedition Repair Kits are also super handy, and field repairs are a breeze. A big part of the longevity of WhisperLites is their ease of maintenance. After all, the gear you take care of will take care of you.
For first-time users, liquid stoves can be daunting. While it would be easy to skip liquid fuel given the flexibility of the Universal, liquid fuel has a lot of benefits that should not be overlooked. There are good videos out there that demonstrate how to use a liquid stove, but in brief: Pump the stove 20 times, release a small amount of liquid gas (two to three seconds with the valve open, watch for the squirt). Ignite this. It will create a big flame. This flame heats the fuel tube, which gasifies the liquid fuel and allows it to run more efficiently. Once the big flames are almost out, go ahead and turn this on. You will need to do this whenever the stove is cooled down. This means that you need to be intentional about how you use a liquid stove. It is not convenient for preparing tea and hot chocolate every 30 minutes.