The Bottom Line: The Omnifuel is an excellent multi-purpose all-season stove. Whether you're backpacking as a pair, simmering delicate backcountry feasts for a group, or melting snow in the winter, this stove has you covered.
This stove has seen a little bit of use over the 2018 summer on a canoe trip and on a June mountaineering trip where we experienced snow and winds up to 65 km/h, though we were well sheltered behind a stout snow wall. Maximum elevation was 2,200 meters. I've only used this stove a couple of times, but I am impressed overall. It cooks delicate meals well with a low simmering capability. It also runs hot, so melting snow and boiling water is fast. I've found that it melted 2.5 liters in about 10 minutes. I do find that the heat is a bit concentrated in the middle, which makes it tricky cooking with stainless steel pots. It is also very loud when boiling. This feature has never bothered me, but I know many other people find it frustrating.
The stove seems pretty durable so far. There are few pieces, and thus few things to break. The casing provides safety from scratches and minor issues. The stainless steel pump and its leather valve is a nice touch, and it inspires confidence for cooler climates.
The stove can run on a variety of fuels. This is a huge benefit if you want to use this stove in a disaster when white gas and LPG canisters may be in very short supply. The alternate nozzles are stored on the side arms, which is a curious choice, because they frequently get grime in them. But it is convenient. Once the jet is changed, you can just screw either the bottle and pump or the canister in. This is quick and easy enough that it becomes practical to bring two fuel types on trips where you may not want to prime in the morning because you need to get the coffee going as soon as possible.
Like all stoves, the Omnifuel will get sooty. The downside is that this collects inside the stove and makes it very challenging to clean; you have to get inside it with a cotton swab to do a decent job. The stove is also difficult to disassemble, but it is a simple stove, so there are fewer parts to clean. Most importantly, the cable is somewhat tricky to clean. Check out Primus' videos for a bit more information.
Overall it's a stove that is a superb choice for someone looking for a mid-weight all-around option.