Tricky one. I find most commentators irritating to awful, and generally end up ignoring them.
As regards crowd control vs commentating, you've got a classic risk analysis. Luckily, what they mostly do is commentate. It's low risk, high profile & everyday (thus important). Against crowd control when it goes wrong which happens rarely, and is critical.
I take your point Airbedane, but let's recognise that they are mostly commentating, and work on that, and (as Zlin said) I have little confidence in some luvvies as to their ability in a difficult situation.
The chap on Sunday at the Pagent didn't impress at first, but he did seem to work the crowd, and did the job for mum, dad & the kids. His intro and silence for the stunning Spitfire display was excellent.
Roger Hoefling (sp?) was the only commentator who cut the mustard for me, but no longer appears at OW, could be a bit dry and dull, but did his homework FIRST and knew his stuff. Franly, most are weak on at least one or two acts - must try harder Curruthers!
John Blake has a lot to offer. He was, however, stunningly out of date on his info in the 80s and 90s OW shows; frankly his notes seemed to be pre-1977. Current info is important!
David Ogilvy used to be excellent, knows OW very well, but has wandered off on a hobby horse or two last few times I've heard him.
James Gilbert was good, I thought, and like John Blake does the avunclular Test Match Special type of job, but I recognise while I like his sense of humour, it's a bit dry and sardonic for some.
No easy answer, but thanks for asking. At the moment I don't go expecting a familiar face atthe mike, but the changes have been better than settling on one candidate, IMHO.
Cheers
James K