The Bottom Line: The Minimo is the best canister stove system for those who want efficient boiling but who don't want to compromise on simmering capabilities. This is the best stove for someone looking for a versatile, compact, lightweight two-person cooking system, though a bigger pot is recommended if you actually plan on cooking.
I've had my Jetboil Minimo for several years now. I use it for mountaineering, ski touring, and lightweight backpacking. It's been used at altitudes of up to 3,000 meters and in the pouring rain after getting soggy inside a damp pack, and there was no noticeable decreases in performance. In terms of design, the pot works well. There is a decent handle that makes moving it about or drinking from it easy enough. The lid doesn't pour especially well, but it is a good strainer that also clips onto the protective heat-resistant protector bowl underneath.
In terms of boiling capabilities, this stove is better than any non-system I have used. It doesn't boil nearly as fast as the MSR Reactor. The Reactor seems to be faster by about 40 seconds at anything higher than 1,000 meters. The Reactor also is much better at deflecting the wind. But these are kinda non-issues. A simple hand in the direction of the wind is sufficient to keep the Jetboil going strong, and 40 seconds is not that much time to wait. And the biggest point....the Reacter, the Primus ETA, the Jetboil Flash....they incinerate whatever goes in. If you are putting anything denser than water, you need to be hyper vigilant.
The Minimo simmers like a dream...better than any stove I've used. Yes, even better then a Dragonfly. The reason is the regulator that is built into the base. This little doohickey makes the stove tricky to turn on; you need to crank the wire valve until you hear the hiss to get it started. But this regulator allows you to drop the pressure to a candle flame once the stove is ignited. Now, the MSR WindBurner Group System is poised to disrupt this simmering reign, but it hasn't been released in a big way yet.
There is also a lot of convenience to the Jetboil that is not found in other systems. The valve is large and glove friendly, so it is perfect for winter. The pot is clipped into the stove itself. If the stove tips over, this attachment ensures that the flame isn't near the ground. It also means you can pick the whole stove up and move it around easily when the winds change, or if you fancy finding a better spot to sit. There is also a pot stand built into the lid, so it's a very stable system. But the best feature of all is the piezo igniter. I thought this thing would have broken by now, but it's still going strong. I will leave water in it outside my tent the night before an alpine start. In the morning I roll over, crank the valve, and snap the piezo, all form within my sleeping bag. In a minute and a half the water boils and coffee is on it's way. No lighters, no lifting stoves, just simplicity.
I only have two gripes about the stove. It is really good to cook in, but the pot is too small for two hungry people. I have since purchased the Sumo pot, which is compatible, and it's a huge improvement. It's still quick, and I can still simmer just fine, but now I can make enough food for two people comfortably. I've done curries, ramen, pasta, stews, and even those finnicky Lipton Sidekick packs with my Sumo/Minimo combo. I'm very pleased.
The other downside is canisters. I hate LPG Canisters for the same reason I hate non-rechargable batteries: It's tricky to see how much energy is left in the container, they are a pain to recycle, and they are kinda bad for the environment. LPG canisters take a lot of energy, and they are bad for the environment.
I would also recommend the extra accessories. The stove mount is nice if you want to use it with a skillet. I have the hanging kit, too, which is rather handy for winter trips where cooking outside might not be in the cards, so being able to suspend it avoids the old knock-over scenario.
So at the end of the day, the Minimo probably isn't the best stove in any one category. It doesn't offer the versatility and options of a Dragonfly, nor is it as lightweight as the GSI or MSR new uberlight canister setups. It isn't nearly as quick to boil or as efficient as the MSR Reactor either. But it is almost as good.