I've used adjustable stems before on my bikes - I think an XLC and a Sunlite. Now I only use them to dial in the length and rise I need for a bike. I never had problems on the hybrids or my road bike, but I had minor issues with the adjustable stem loosening or shaking on mountain bikes.
On my hybrid, I've actually gone back to the stock stem; my road bike has the original stem back on, flipped and a couple of spacers above the stem; my mountain bike got a longer stem with less rise than the stock stem.
Short story - use an adjustable stem to find out what rise and length you need on a stem, then replace it with the right sized stem.