I have the
KS Lev, and it is fantastic. Super reliable. Others I know would say the same thing. There are a few good brands out there making solid dropper posts. You can also look into the
One Up Dropper. Do not get the Rock Shox. They make great stuff, but droppers are not one of them. People have problems with getting air into them and then the dropper not coming back down. The fox ones are sweet, but pricey.