Haven't played much (waiting for weekend), but my experience is opposite -- battery drops faster, I don't see any performance improvement (ie. faster scrolling, opening apps, overall performance feeling), have installed android support and use c:geo for geocaching with offline maps -- scrolling and zooming offline maps are waaay faster on J1. Jolla C also don't find my position while inside (SIM inserterd, GPS on, option for A-GPS on).