This entirely depends what you want them for. You will never be able to write a whole tune in one box, but if you want to make loops and have a bit of fun I don't think anything's wasted.

I have the ES1x, and swear by it. It's a key live toy and all the loops from it I record as audio to the DAW to use in finished tunes.

It also kept me sane when I was in hospital for 3 weeks...

My advice is try and get to a store and have a play on one (getting harder, I know) and see what you think.