First and foremost, the web design should NOT hamper with any search engine optimization (SEO). This is the number one complication with Flash files, that and the fact that Apple does not support Flash and therefore your gorgeous website won’t be so beautiful on iPads, iPhones or any other systems running the Mac OS.
So should you steer clear from Flash? If you are simply selling goods, then my advice is no Flash whatsoever. If you are a designer showcasing your skills, the Flash should be a part of your portfolio but not your main page. Some people are mesmerized by a Flash intro, once it loads, and will demand this for their sites. But look at the web’s most prevalent sites. How many of them use a Flash intro? Answer: zilch.
Even sites like Yahoo that used to use Flash for video playback, now have their sites designed to detect what kind of device is trying to access the video and will provide Mac OS users with an .mp4 version of the video file.
The bottom line is that there is no one answer regarding site design and how pretty your site should be. The most important aspect to consider is knowing your potential customers and what will appeal to them. Think about if you were selling the product in a brick-and-mortar store? Would your customers want to find you on Rodeo Drive or in a strip mall? If you were selling your products and services door-to-door, what would you wear? Answering these questions will not only remind you about who your customers are but also get you mind going as to how your site should be designed.