I worked in web development for over 5 years... Flash intro's are sooo 2001.
A great deal of people (myself included) won't wait for them to load... unless it's a design site.
The bail out button came about through Flash intros losing hits on sites. People were just hitting the back button and going elsewhere.
If yours is going to have a lot of images in it, it'll be on the slow side. You can only compress images so much before they start detracting from your site... I hope your bloke's not doing cheesy text effects as well.
Flash intros are really not very professional IMHO.