So here goes.  More than you ever wanted to know about  MSR Windboilers.

I finally weakened and bought one, so what follows here are mostly just impressions and opinions.

I have previously owned a JetBoil Flash circa 2012, so that is my only other experience.

I think the MSR is generally better workmanship and the radiator assemble was more complex with some impressive plasma or laser welding for better heat transfer.
The MSR marketing team took every liberty in describing features.  The tiny little Pack Towel is paper thin and about 3” square.  Its only apparent purpose is to keep the fuel cell from making contact with the inside of the pot.  They describe the sleeve as “insulated” but it only consists of the nylon fabric with a piece of oval slotted plastic giving it a .075” dead air space. No actual insulation like the JetBoil sleeve that sags horribly when hot.  The MSR does have a ridged plastic piece under the handle loop to keep knuckles away from the hot pot and it works very well and snaps firmly into place. 

I cannot speak about the fuel efficiency of the Reactor burner, but I would guess it is better.  I do believe their claims of being windproof  as long as the pot is in place and the burner is on high.  Hitting it with a compressed air hose to simulate wind on Bayley Bay, I could not blow it out unless the burner was throttled down.   If it does go out, it cannot be relit without removing the pot first.

The down side to the windproof  feature means you cannot see the flame to operate on low power if you are trying to warm or simmer something.  Sound is also not a great indicator.  You can sort of gage it by valve position, but I would guess that changes with air temps and how full the fuel cell is?

If you hear the burner sputtering on a minimum setting, it is on the brink of going out and any breath of wind will finish it.  Just enough flame to keep the burner covered works well.  At that position the time to boil 0.5 liters of water goes up to 9 minutes in zero wind.  On high setting it is only 2:20 minutes.  I am guessing that minimal setting will work reasonably well with simmering in the pot or the frying pan accessory.  I also ordered the pan but have not yet received it.  It does not lock onto the burner like the pot does, but can be easily lifter off to inspect the flame size.  Getting a visual on flame size is impossible, except in dim lighting.  They actually put a glow wire on the burner so you can tell if it is lit or not in the daylight.  Back to the frying pan …………it is ridiculously priced at $64 .

Bringing this full circle, now that your coffee or meal is hot, keeping it that way becomes a problem.  The so called insulated sleeve is too hot to hold comfortably with boiling water and the magic radiator on the bottom is now doing a thermal nosebleed and giving up heat to the wind.   My only firm suggestion here in this whole diatribe applies to any similar system with a 1 liter pot.  I bought an Optimus Heat Pouch  made to be used to keep  freeze dried foil pouches hot.  It is also the perfect size to slide the 1 liter pot into, sleeve and all.  It also has a nice pocket to slide your hand into to hold it.  It makes a huge difference in how long it takes the pot to go cold.

Thanks for listening.  Apologies for being so long winded.

Thanks again to everyone who offered suggestions  to my questions.

Regards,

MossBack