I've been waiting for a replacement of the P155 since I sold my P120 back in 2011. It's always nice to have an 88 key, lightweight keyboard. I've used them for weddings and other events where I need weighted keys. With the price of the P255, it makes my choices as follows...

Yamaha P155 (with speakers)
Yamaha P255 (with speakers)
Yamaha CP4 or CP40 (great sounds and only 38 lbs)
Roland FP50 (with speakers and audio playback)
Casio Privia PX-5s (Good sounds and feel... Controller features)

The P255 looks great and if simplicity and built in speakers are my main needs, I may have to get one!