I'm looking to replace my standard crank with a compact double but don't know a whole lot about the various brands of cranks, other than Shimano. I'm looking for something at the 105 or ultegra level. I can get the Shimano, of course, but am wondering if I can get something just as good, and save a little, by going with another brand. I'm not wedded to any particular brand. I would be putting this on a bike with 9 speed Ultegra brifters (6500), an ultegra (double) front derailler (6500, I think), and a 105 RD. Any suggestions?