For other people thinking about ordering online from a place like MaryAnnBridal.com my advice would be to know from the get-go that you are still going to have to bring it to a tailor for alterations. I knew that even when you provide your measurements online, there is nothing like being there in person to see if it really fits. I dropped my dress off today at a local tailor who got great reviews on Yelp.com. She's going to hem it up, fix a funny pleat, and will even make some straps for it (at my request) using the excess ribbon from the lace-up back.
There may be parts you don't like. As with the “real” version of the dress, I'm not impressed with the flowers on it. Even if I had purchased the $1,000 version of the dress I’d seen in the store, I had planned to replace the flowers with better quality handmade ones from Etsy.com and that is still the plan.
I also noticed that because the makers of these dresses are basing the style and color on a photograph of a designer dress, there will be differences, particularly in color. In my case it worked out serendipitously. The designer dress I liked in the store was ivory and champagne/coffee color, but in the picture online and in the dress I received, the dress is white with a yellow/gold bottom. For me, these colors are actually better since yellow goes with the dresses we got for the bridesmaids and fits my summer wedding. However, if I had had my heart set on ivory and champagne, I would have been disappointed.
If you are flexible and willing to accept/make some changes to a dress, this is a great route to go and an alternative to bridal boutique shopping. It saved me a lot of money (in the end I anticipate saving 50-60%), it was faster than going through any bridal shop (took 6 weeks), and the money I saved by not buying the expensive dress can go in part towards making some customized changes to it (straps, flowers, etc.) that will make it truly unique.