I've never heard that about a Sram FD, nor have I experienced any difficulty. I've built up bikes myself with both Shimano and Sram and they are 100% identical as far as ease of setup and maintenance. If either bike has a better crankset, go with that one. The quality of the chainrings will make a much larger difference on the performance of the drivetrain than anything else will since you're comparing two quality products. Also, check out if either comes with better brakes, though I believe both come with Tektro.

If all else is equal, go with the purdier one.