Good, but order twice as many as you need.
I bought these for a home office because I could not see the yellow highlighter on my paperwork under the light from "warm" CFLs.  Definitely a much whiter light than you might be used to (the "gas station mini-mart" look that another reviewer mentioned), but you can get excellent results if you put one of these and one "warm" CFL in a 2-bulb fixture. They're the same size as a generic 100W light bulb, so they fit any fixture; but note that they are a bit slower than most CFLs to come up to full brightness, maybe 30 seconds or so.<br /><br />Beware the miserable factory packaging: a tight-fitting cardboard box with zero padding.  I ordered a 2-pack, which arrived with one bulb broken. Amazon took them back and sent a replacement, and again one bulb arrived broken.  I'm going to get a third package, but this time I'll hold on to the one good bulb, so I can send back two broken ones. (Assuming they don't send me TWO broken bulbs, which is a distinct possibility.)  This is despite plenty of airbag packaging from Amazon -- I suspect they're being busted further up the supply chain.<br /><br />Compared to Costco's 8-pack prices on "warm" CFLs, these are relatively expensive, but with 50% losses in shipment I suppose they have to charge twice as much.
Rating: 3 stars