Found all three of these new Walkers flavours in various shops now and can give an opinion!
Firstly, the rebrand to 'unbelievable' is maybe a bit of a reach for the meat flavoured ones as lots of the meat flavoured Walkers were accidentally vegan anyway. I understand why they've done a cheese one as loads of those contained milk.
BBQ Pork Ribs- mainly tastes of beans, which I'm not angry about. 7/10.
Grilled Cheese Toastie- weird synthetic taste and smell. They may have overdone one of the seasonings. 3/10.
Flame Grilled Steak- best of the bunch and reminds me of other steak/beef flavoured crisps. 9/10.