I find with Flash it can be easier than HTML, but it depends on how well you work.
HTML Coding
You can create your template and send it to imageready, slice it up and then prepare to recode it. Then it's a matter of setting up your tables and using trial and error to fix any bugs. I can usually create a Html website within 2 to 3 days. 1 Day for design, 1 - 2 days for coding and content.
Flash Design
You can also create your template but you can't really send it to imageready... well you can but it's not recommended. If you want a transparent graphic you must save it as PNG and it is orquad copying layers into a new document with Blending Options applied.
I found with this website (Im not a talented flash webdesigner) I had to copy the parts out photoshop into new documents. Save them as PNG's then import them into my library. And this can be a little more time consuming than slicing your image. But when it comes to the coding, there is little coding involved. My site is no more than 10 frames, 2 for preload and 1 per page.
Buttons are orquad because of the process of turning an image into a graphic then into a button.
But you don't have to bother with creating table code and trial and error, which can be quite frustrating or time consuming for some. Which is nice.
I also noticed with my design if I want to update the template, I must rename the file and update my php file, otherwise it wont recognise the change.
