Oh snap, I didn’t realize LG also had multiple models within the same series. Samsung does that and the low and midrange almost always have lesser quality hardware. I haven’t heard of them creating lag like this but if you have a choice, *ALWAYS* buy the high-end.
In this case I guess you fit into the “trying to do alot of processing with slower hardware” category. It’s a shame manufacturers do that but it’s not likely to change anytime soon. Unfortunately…
I’d never thought to take a console into the store but if this becomes much more widespread I can definately see it becoming a popular thing to do.