I dont know if I would call it a stores forum so much as a community forum that happens to have a store. Well I cant see the first picture let alone no specs are posted but assuming they are the same product, I can tell you why I buy from mp3car.
Yes the price may be more then others but like most things in life you get what you pay for.
For example: I made a large order and couple things were messed up but by far mp3car went the extra mile to make returns and exchanges as painless as possible compared to other online retailers I have had to deal with.
Also it helps support this site where you can get pretty decent support on you carpc needs.