In regards to Arriva's interior spec of this period looking like a throwback to a 80s bathroom, it's a matter of personal taste by and large. Speaking for myself (I know, hardly an authoritive source!), I don't mind it all that much. Hardly the worst by any means, but not the best either.
You all can go back and forth about the nature of the service cuts McGill's have made over the years 'til the cows come home, but let me pose this question: if Arriva were the ones making these changes/cuts in McGills' place, how much outrage would it generate? Rose-tinted specs are all well and good - I should know: I wear them often enough! - but they don't often, if at all, gel with the realities of keeping a company solvent, viable and profitable in the face of a ever-evolving market and industry, I'm afraid. While I personally don't have any time for the two guys at the head of McGill's, I can begrudgingly acknowledge that they are shrewd businessmen. Sound like anyone else in this industry we know?
While some of McGill's purchases in their post-ASW takeover expansion faultered and thus withered away (the near clean sweep of the Monklands indys and the McColl's of Balloch takeover, am looking at you two in particular), I think they were in the best possible position for a pandemic and all that entails suddenly rearing it's ugly head, which is why the Xplore Dundee takeover (well, more it's timing than anything else) will never not be odd to me, regardless of it's prospective success or failure. It's early days yet at any rate, so am gonna refrain from calling it a busted flush for the time being.
As for the age of vehicles ASW - the main topic of this thread let's not forget! - were operating in the late 2000s: Olympians - heck, double deckers in general - were always in the minority when compared to saloons in the ASW fleet and, given it's size (especially when compared to the likes of First Glasgow), their precense would've had a fairly noticable effect on it's age profile in any given year. That said (and I'm open for correction here), I don't think the intention ever was to give them a complete refurb top to bottom; an internal spruce-up/retrim with new blinds to eek out a few more years' use from looking at the pics was the order of the day, at least as far as I can tell.
Moving on to the saloons, while some brand new stock had made it's way into the fleet in the 2008-09 period (all from the Volvo, Scania & DAF/VDL catalogues), a good portion of it was made up of ex-Clydeside & London vehicles mixed in with stock both from ASW's first few years & others parachuted in from other Arriva divisions. While the end result was a varied and rather mish-mash selection of chassis and bodies, most were kept fairly tidy and to a presentable standard. Of course, some vehicles let the side down - same with any other division of the big companies; Arriva were/are hardly unique here - but on the whole it was on par with or better than it's fellow Arriva subsidiaries in this regard.
Whether or not that last part is a good thing is bound to be debated ad infinitum. I'd expect nothing less from this forum.
While not a integral part of my childhood/early teens (First Glasgow and a motley bunch of independents took care of that), I still remember their motors buzzing about Glasgow. Hard to believe it's been over 9 years since they sold out to the 'lads in blue'; honestly doesn't seem like it's been that long. Two abiding, but relevent TV memories I have is at least one of their V-reg Wright-bodied B10BLEs appearing in a Series 2 episode of Still Game and one of their Metroriders in a Series 4 ep. with Robbie 'Davey The Bus Driver' Coltrane at the helm. 
