I found a decent video comparing the 29ub65 (pretty much the same as the 29um65) to the swift (should be pretty similar to the benq) and going by this video, there really is very little difference when viewed head on (some areas the LG looks better and in other areas the swift looks better), no idea about calibration etc. though:
That's very interesting... wouldn't have expected that. Assuming it is accurate to real life, not just through the camera that's filming it? You'd probably find the moment you moved 15-20 degrees left or right, things would change very noticeably, but for head on viewing (as is the norm anyway), I'm really surprised how neck and neck they are.