Thats odd. I have a Tmobile Note Edge with a kit kat custom rom by sbreen and I'm using ss launcher. Very rarely do I find it "laggy". Camera is great, can open apps in floating windows, Xposed modules add much functionality. Love the pen. Can have access to a lot of stuff with a simple swipe on the edge. Can also chroot fedora. Multitasking is not up to par with, say, N900 I would worry more about security related issues than lagginess. But overall it is the best phone I've ever owned.