The ambassadors really don't bother me that much, I just don't feel like they impose themselves much on me (which rather suggests they are a waste of money)... indeed, apart from when they get announced I feel like I hardly see them at all. So not really that big a problem.
My comment regarding the ambassadors was that the ambassadors in general fit well with the slogan of don't crack under pressure in my opinion.
I think the reality is that if you are any sort of enthusiast or collector then it is very likely brand ambassadors do much for you. They are there to bring new and constant awareness of the brand to many different consumers as well as non-consumers (I.e. Plant the seed for when they are potential customers).
Yes generally they do, sportsman in general are a good pick, even if some might seem odd if they aren't particularly famous in your region. Not sure what pressure Alec Monopoly is under, or Chris Hemsworth?
I honestly can't think of anything I've bought or been swayed towards by an ambassador. TAG logo's on F1 cars is another matter.