Ever since I have been in the real estate website business there has been a dilemma between the look of the site and the functionality of it. Some of the features that make your site beneficial to users detracts from the design and layout of the page. If you load your home page with 'eye' candy', then it is often difficult for users to find the search button. If that wasn't enough of a problem, now, more than every you must consider the impact of your web design on search engine spiders.
My mentor always repeated - 'spiders are blind'. Since a search engine spider doesn't have eyes like you and I, the graphics you place on your home page goes unnoticed. There are many home pages that I have reviewed, that are nothing but graphics from top to the bottom. If I were a spider there would be nothing to read and no way to index your page, save the image alt tags if there are any.
Now - on the other hand, I hear from my clients that do have eyes, that their site needs to look great. When a real potential customer visits your site they need to get the message that you are a serious professional, and that you know about marketing. Your web site needs to clearly communicate this message to potential buyers and sellers. Now that nearly every REALTOR has a web site, you need to differentiate yourself among them. If you have an 'old style' web site with a Christmas tree type design, you may be ranked well for your spider friendliness but you may be turning away prospects just by the looks of your home page.
What is your opinion between looks and spider friendliness? Have you noticed that some of the sites that rank well don't look very good? Have you noticed that some of the web site companies out there have sites that look like magazine pages? and there are no keywords in sight?
I am often torn, but my vote goes for spiderability, usability, then looks. (Looks aren't everything ;)
Spider friendliness wins out with me. You need to have a good looking and informative site, but the data needs to be there as well.