I have one, they are very good, making lovely chips. I often do a mix of parsnip, sweet potato, carrot and normal potatoes, sliced round because I like round chips. I also cook them in the oven though, with just a few squirts of fry light. Not sure there's a great deal of difference in the taste. perhaps the Actifry uses less power than putting the oven on for the time needed but this is just a guess.
You can also cook prawns, chicken etc in them and it doesn't seem to dry them out like an oven can sometimes.
if you can find one on offer, I'd go for it!