Hi, Just wondering whether there's any lag or slowness experienced when running more than one 4K/5K monitors with 450/455 GPU. 460 seems to have no lag at all driving two LG 5K monitors (as demo'ed in couple YouTube videos). I am planning to use one LG 5K and one 4K (LG 27UD88), and sometimes a 12.9-inch iPad Pro connected via Duet. I don't want to wait to get 460 and if 450 itself can do the job, then why pay more? Thanks!