-
I'm guessing it comes down to the brake package you get... with 105 you get mechanical disks, but with SRAM you get hydraulic... there's one in between the 105 and SRAM were you get semi-hydro disks (sky blue frame), the brakes will be beefier than 105, but with full hydro, you get way more braking power... apparently to loose 60% with mechanical. I've never used SRAM before either, but I hadn't used Shimano for donkeys so it wasn't a biggie for me.
Do it, but you could get a SRAM version with hydraulic brakes for another oner