I made it to the area on Thursday. I stayed in Middlesbrough to ride route X93 to Scarborough, but started off with route X4 to Whitby to see more of the coast (and vary my buses slightly).

Anyway, my East Yorkshire buses were

Enviro 200-MMC 280 on route 7a to Wheatcroft Avenue via Seafield
Volvo B9TL (refurbished) 791 on route 13 to Bridlington
Volvo B5TL-EvoSeti 815 on route 121 to Beverley
Enviro 400-MMC 923 on route X46 to York

I found the seating on the new buses the most comfortable for some time. Certainly more so than the LNER Azuma with similar colours!