Budget head unit - Mirroring or Android Auto

[.Adam.]

I am looking to get a reasonably cheap head unit to replace the double din unit in my wifes Nissan Note. We both have android phones, and the head units I have been looking at offer mirroring. I've not had any experience of this, is it any good? Can you use things like Waze or Google maps?

Cheap branded heads seem to be around the £150-£200 mark, the cheapest Android Auto heads seem to start around £300, is it worth the extra outlay?