I haven't found the UI that laggy and tweaking transitions made a big difference too. It would be good to have transition tweaks to be included the image. Haven't yet tried the latest image.

I wonder if there is something using the ram and cpu on the back, dredlock. Like with fremantle the Opera browser feom devel repo left browserd to work on the back so that it made the device unusable unless rebooted. Do you have conky? With that it is easy to see what stays on and is making device to be laggy.