Security is our top concern on
halfpricedigital.com. We are currently looking into allowing users to register with longer passwords. As you saw, we do have a GeoTrust 256-bit SSL Certificate.
Our main security benefit is that we DO NOT offer an escrow service. By not offering escrow, you don't have to worry about your escrow funds getting stolen by someone who hacks our site, since we never hold any of your funds. We also don't run the risk of being shut down for regulatory reasons. If you'd like to use a 3rd party escrow service for your auction, of course you still can.
As for the CMS, all the BTC auction sites (other than maybe bitmit) are running auction scripts that they've modified. We chose an auction script that has been around for a long time to be sure that it was properly battle tested and then modified it to add a Coinbase payment gateway so you can buy/sell with BTC.
It'd be great to get your thoughts on the site after you register and give it a try. Thanks for your feedback.