Hi, i own Sony KDL-55W905A 
and with latest software update i have experience when watching movies stuttering and random frame drops on any movie. That was never happened before that stupid update. I tried to factory reset the tv but that didn't fix the problem,i tryed to play moves from the different hard drive and still didn't fix the radndom stutter:(. I don't know what to do and now It is so frustrating watching the movies..I hope sony will do something abut this issue soon. 

I would like to downgrade this new firmare and put the previous one that worked just fine..i hope there is a way to do that.