Does it work? Yes, it does. And quite well, at least on late-season Pacific Northwest mosquitoes (admittedly not the most vicious denizens of the insect world). It works best on the areas it covers, of courseending that annoying problem of bugs that bite through shirts. But it gives off enough of an aura that unclothed areas get some protection, too. Add a little deet-based repellent to bare skin, and you'll be the bane of bugs everywhere.
Alas, in time it does wash off. Ex Officio says in 25 washings, which isn't bad. You'll also want to wash Buzz Off clothing separately from regular clothes. And, no dry-cleaning.
Buzz Off does add some to the cost of a garment, but not too much. Ex Officio's Buzz Off-equipped Lite Long Sleeve Shirt, for instance, sells for $79about $10 more than similar travel-type shirts that lack the repellent feature.
If you spend a lot of time in buggy country, and don't like liquid repellents, Buzz Off is definitely worth a try.