My buddies are jealous in the morning...
This kit was an add on after I had used the jetboil pcs for a few trips. the couple ounces that this kit adds is worth its weight in gold every morning I'm sipping fresh coffee 15 minutes before everyone else is. I've also used it for loose teas with great success. Added bonus that it packs into the pot even with the fuel canister in there with the burner.
Make sure your coffee is a coarse grind and you take your time pressing it out or you'll be sucking down grounds.
The small amount of water to clean it out afterward is a minor inconvenience if you're far away from fresh water supplies but I generally have my filter with me.
If you drink coffee like I do this kit will be invaluable in the field. Snag one and get ready to bring that simple comfort of a hot cup of gourmet joe with you on the trail.