I've just read Daniel Robinson's article "Flash needs a content kill switch" in today's issue (26th February 2007) of IT Week in which he expresses his opinion that many web designers over use Flash content. He is particularly upset by its use by advertisers and notes that it presents serious usability issues.
I fully support his opinion. I strongly believe that web sites should be mainly constructed using HTML rather than Adobe Flash content. I generally only consider Flash content to be acceptable where it is being used to enhance existing content. This might be by providing a product demonstration, fly-through or some other interactive presentation in addition to HTML accessible content about the same topic.
I would also concede that sometimes a small amount of Flash content can enhance the visual aspect of a page, but the page should certainly be capable of display without the Flash plug-in being loaded (ie: the content is optional) and should not be an essential part of the message.
I very rarely wait for Flash-only sites to load. However, if a generally non-Flash web site sufficiently fires my enthusiasm about something I am interested in, I will wait to see its interactive Flash demonstration - but I like to be given the option so that I know what I am letting myself in for.
My lack of enthusiasm does not appear to be unique. I have come across many people who have cursed Flash content - most recently Daniel Robinson.