No personal experience with Baer, but the consensus on them from some other boards I visit is that their entry level stuff is rebadged corvette stuff. If it fits a 14" wheel, then it isn't going to necessarily be better than the stock stuff you may have as they tend to use 10.5 or 10.8 rotors, which are comparable to stock 14" wheel stuff anyway. The dual piston calipers may be a little bit lighter and provide a little better feedback than the stockiron, single pot units, but otherwise, no big gain in using them over your OEM set up.
Additional braking force comes more from leverage than swept area, so the larger diameter rotor provided greater leverage for stopping, which is why 13 and 14" set ups are so popular with the 17-19 inch wheel crowd. The biggest rotor you can fit in a 15" wheel is 12.19, which will be a special kit, most likely from Wilwood, Red Devil or US Brake, but others may have them too. Expect to spend a few grand on this type of set up. Using stock style stuff, 11.75 is a bargain way to get close to the same leverage without spending a fortune on the system, but it all boild down to intended usage, personal preference, and budget.