They are very nice flats; middle of the road tension. Really smooth, both in sound and in feel.
I think you'll find that flats will last on your bass as long as you want. If you want the sound of flats, you'll probably like them more the longer they're on your bass.
Go to GHS's website, they have some videos of Dave Pomeroy playing the Precision Flats. Pomeroy could make a shoe sound good, but you'll get the idea.
Also, the Lakland site has a lot of sound clips that showcase their basses with flats. The flats are the Lakland Joe Osborn Flats--made by GHS, and basically the same string.