So the "Sleek" in the title appears to refer to its narrower design. In my case, that's a good thing. The old bulbs in the existing light fixture used to touch the backplate. Now there's about 3/16" room. I like the 4200k color. It's nice and bright without overdoing it or tripping into harsh glare. No noise and instant on. It would be nice if they last longer than the Sylvania bulbs I used to buy at Home Depot. Ill try to remember to let you know in about a year and a half.
20191106 - These CFL bulbs last just about as long as every other CFL I've used. I bought 4 bulbs on June 28, 2018 for use in my 2 bathroom sconces over the sink and placed 2 new bulbs in them shortly there after. I had to replace one of the bulbs about 4 months ago and the other last week (about 18 months after installing). The good news is, the older bulbs don't change color or go dimmer as they age. That is to say, when I put a new bulb in one of the sconces, it looked the same as the bulb in the other sconce. Other types of bulbs I used in the past had to be replaced in both sconces at the same time because the newer bulbs were whiter and brighter than the bulbs that has been in there for a while.