I feel your pain man, having worked in the retail industry I know first-hand that most of the "salespeople" don't know anything more about the products than the little blurb cards in front of them tell you.
My recommendation would be to find a consumer site/online forum that specializes in just electronics and includes reviews and customer feedback, I've been burned by doing research and making a decision based on manufacturer supplied information alone.
http://www.cgnetwork.com/index.cfm?act=consumer would seem to offer what you're interested in, but at the moment it's being finicky.
Last but not least, having dealt with computers and electronics from a marketing and support standpoint as well as a consumer, I can tell you without hesitation that you get what you pay for. If two things have the exact same statistics yet one is cheaper, they cut corners somewhere to reduce costs, they're not going to give up their profit margin.