There's Coastliner 308 Gemini's on the X9 and X10/11. Blyth's allocations are all over the place today, even with the MAX spares out!
There's also a Coastliner 306 StreetLite out and about on the 55 and at least one ALX400 on the actual 306.
RE: Arriva North East: Rare & Odd Workings - February 2016