For those who have not checked out the MSR WindBurner All-In-One Iso canister system, you owe it to yourself to do so. The Windburner adds to convenience the solid wind-proof performance of a radiant burner design as well as a secure but easy on/off of the pot and a good quality construction.
As we know, a 1L pot can't boil 1L of water (nor a 1.8L pot that volume), so for heating water for 2 meals or one meal plus coffee/tea, either two runs of the 1L pot or 2 separate 1L pots are needed. Now the 1.8L System or the 1.8L accessory gives that bit more than 1L boil capacity for making two meals or a meal plus coffee and extra hot water.
Additionally, the capacity of the 1.8L pot affords packing an 8oz canister, if one wants, or even packing the 1L system and 4oz canister (except maybe for that system's cup) inside the 1.8L pot, so not only enough water can be boiled for the meal, but as one preps the meals, the 1L can boil the water for their coffee.
Lastly, MSR has provided a much improved canister stand for better stability with the larger (or smaller) pot as well.
Yes, a few ounces heavier, and another inch or so in diameter larger, but a good solution for 2 or even 3 enjoying the out of doors.
Next in view - the MSR skillet with heat exchanger designed for the WindBurner. Heard good things about that. Sure, something more for camping than trekking, but it adds value and versatility to the all-in-one concept.
This review was written in the old system and had content requirements that are different than reviews written today.