I went with a Pioneer unit recommended by a local car electrical place; needed a small harness making up, but gives me waze/GMaps through the phone, DAB radio and keeps all the normal functions like camera/clock, etc of the old one.
Cost about £350 but is way better than the old one.
However, electronics move on quickly and it could well be that Alpine make great new units, too. Ask around some local electrical places for what they recommend, I suggest.