IME:
Spesh are quite narrow (but have wide versions but not generally in the UK
Shimano are quite narrow (but have wide versions available in the UK but often very limited sizes)
Sidi are quite narrow (but have wide versions available in the UK but often very limited sizes)
Bont aren’t too bad but still quite narrow mid-foot, the toe box is roomy though so depends where you width is
Mavic are so narrow they’re like some sort of Chinese foot-binding device
Northwave are OK fit (although only ever used their winter boots so not sure if they’re a roomier last than their standard shoes)
Normal shoes and trainers mostly fit me fine (apart from some Adidas models) so I don’t think I have especially wide feet…