I also have an aerogarden.
They do work well for germinating seeds (you can buy this styrofoam insert for it with 60 holes in it and foam sponges with nutrients in them, it's pretty nice), but getting your sprouted stuff out can be a bit tricky. The roots go everywhere and can tangle with other sprouts' roots, and that growing sponge thing is pretty much stuck on your plant for good.
After the sprouts grow a bit and you're ready to transplant, you have to be very careful about it, going from the aero to a pot of soil or the ground is an immense shock for the plants, and you can lose a lot of sprouts if you're not extremely careful in how you do it.
As to growing the pepper plants for harvest? No. They stink on ice in that area.
For growing herbs, they rock. I wouldn't be without mine for any reason.
IMO, it's easier to just start the seeds normally, and I know for a fact that they're not a choice to actually grow the peppers to maturity.
That said, if you like fresh herbs, by all means buy one, they're great.