Big images look great on website - just like they do in print. Most of the templates I've designed recently support bigger images than before. I've gone as big as 900x600. Does it have an impact on visitors? Yes. Should I keep going bigger? No. We still must design within constraints.
Constraints are good. They are like boundaries that keep you safe. And the constraints of your web design come from your visitors - not you and not other photographers.
Stephanie, that teacher from Thousand Oaks - you know, the one that's getting married next year and is considering you to be her photographer. Guess what? She doesn't have a 30" Apple Cinema Display. She has an iMac or a Dell laptop.
Focus on a smart website, not a big website. Clean. Easy to navigate. Search engine friendly. Instead of asking photographers to critique your site, how about asking your parents?
Remember, design for your visitors, not other photographers.