When they work, they work well. Of course a technological limitation of SSDs is that they have a finite number of write cycles. But for a typical user it means they'll "use up" their drive in a period of something like 5-10 years or more - and since the drive will likely be obsolete by that time it's really not the huge issue that a lot of people seem to think. But you do need to be a little prudent about what kind of files you put on the drive in order to avoid excessive writing.
The biggest real issue that a lot of people seem to have is firmware issues. The firmware in an SSD is very complex because it needs to handle "wear leveling" in order to extend the life of the flash memory chips. And it seems like a lot of new drives have bugs that have to get fixed with new firmware versions. For that reason I'd recommend not buying the very latest drives, but rather wait until they've been on them market for, say, 6-9 months to see how robust their firmware turns out to be.