I need a full-featured asp.net E-Commerce solution for a project. It needs to be easily extensible as I need to extend it to integrate with a custom Flash based personalization engine. It should also have a great administrative back-end that handles inventory tracking, report, labels, shipping, ... so that the client can really use it as the basis for their business.

I've used quite a few different E-Commerce systems including OSCommerce, Zen Cart, Catalook, and eTailer. While I was impressed with Zen Cart and eTailer, this project is big enough that I want to try a more serious, commercial offering.

I'm particularly interested in thoughts on aspdotnetstorefront, BVCommerce, AbleCommerce, and MediaChase.

[UPDATE] I've done quite a bit of evaluation since I posted this question and will give some of my findings below:

BVCommerce - The price point is nice, the product seems fairly well regarded, and I've heard good things about customizing/extending it, it just doesn't seem like it's going to meet my needs as an Top Tier ECommerce solution. After viewing the tutorial videos, the Admin interface just seems too basic and outdated.

aspDotNetStorefront - The integration with DotNetNuke was it's biggest selling point for me but after reading peoples opinions, it's integration seems quite weak. It's sounds like there's a significant learning curve and the architecture just doesn't sound like it's as clean as it should be.

AbleCommerce - After a rather thorough evaluation, I have selected AbleCommerce for at least my next project. The Admin interface is beautiful and has a nice list of features. The E-Commerce portion of the user side is very well done, highly skin-able (using Master Pages and a couple other techniques), and the checkout workflow has all the features I need while still being very clean. Source to the API can be bought for $500 but you generally won't need it. There are some 3rd party modules available but there's not currently a large market for these. The biggest glaring weakness of AbleCommerce I've found is their CMS capabilities are very limited and not at all well suited for a non-technical user to make most site content updates. But I have a good solution for that that I plan adapting into AbleCommerce. They will automatically generate a site for you to play with to your heart's content for 30 days. It is defniitely worth checking out.