I think the Enviro's are 50/50 and so is ADL but I think ADL are now giving Wrightbus and even Volvo chassied buses bar the B9TL, a good run for their money. My perception of ADL used to be influenced by this and the main culprits were the ones engined by the 8 litre C series Cummins units:

- GNE V/W XXX PNL / SCU / EGR Lolynes overheating and getting temp sensors removed and them also strugglimg when the Coaster got extended as well as slightly struggling on the old 21/22 Angel services.

- Arriva Northumbria WXXX RBB ALX400s struggling on the 308 and even being rested on Sundays in favour of Palatine 2s when they were at Jesmond on the 306. Never rode one on the 602 but I have a very vivid memory of one when it was only a year old (circa 2001) broken down on the Redheugh Bridge approach slip road next to the Shell Garage with it's hazards on.

Now, I think the following factor applies mainly and in general, I do like ADL a lot now but I think it depends on who is looking after them too. Blyth and Redcar gave some of the 57 plates a very hard time but Ashington did look after theirs which were bought for the X31 / X32 / X33.