Many from the usability and standards-aware end of the web industry find that some Flash implementations work against users, not for them, that many Flash-based sites do not comply with web standards, and many do not meet accessibility requirements.
So who is your site for ..? What range of devices might your users want to view it on? What do you want them to take from your site, or be able to do on it? What tools and technologies best make those things possible, against your range of target platforms ..?