Same here, I was used to the super quick response on my old LG 47 in 550T.
I see that LG are going to release a complete update for our TVs soon; A sort of 80% WebOS 2.0 see http://www.cnet.com/news/lg-updates-2014-tvs-to-web-os-2-0/
Great, the download is now on the UK LG Website and I have downloaded it for the install from USB stick. For some odd reason the auto update on the TV does not find the update.
I have had a 55EC930V for two weeks now and WebOS is so slow compared with my five years old LG 47in 550. Sure enough switching off simplink speeds things up a lot. But then ARC no longer works. Any way of still having ARC and disabling simplink?