those are U-brakes down there. they work pretty well, but it depends on what you will be using the bike for. if its street only, not a problem. if you plan on riding off-road you may have problems with brush getting caught up on the brakes, and if its wet out, the brake will get swallowed in mud.

personally i think chainstay mounted U-brakes look pretty cool, but don't perform well off road bc of the reason listed above. one of my bikes is an '88 trek 850 with brakes mounted in that style, cool lookin'.