Open Beta GUI very slow and clunky

There is one thing I don't understand about this new GUI, I like the looks but after knowing how slow the performance on the old GUI was, why is the new one even slower and demanding even more resources from my pc? On my laptop I barely have time to select my pick intend and banning or selecting a champion takes longer too. Why isn't this GUI faster and lighter? I mean, it's not that hard to make something like this lightweight, but I guess it's running on Java.

This is my main complaint about the new interface. It needs to be fast and lightweight not feel slow and using up so much resources on my pc. Just fix it, it's not that hard. I mean I'm not playing Call Of Duty with graphics settings to the max, this is LOL we're talking about.