I checked for software updates today and was offered 1.03.52 as an update to my installed 1.03.51. I clicked Install and it took about 5 minutes to install during which time the screen went black for several minutes. Eventually it came back, showed me the installation proceeding, and completed, and then the box rebooted itself.
Everything then checked out OK.
The response time changing channels seemed fine to me.
I did wonder if sometimes it ignored a remote control signal and thought it might be was because today is very bright and the room has bright sunshine in it. More testing showed that if I actually pointed the remote control at the box - I normally don't bother as it works pointing in almost any direction - it always worked every press.
Going to the All4 player showed an immediate improvement. Previously on 1.03.51 it was so slow - minutes - that it was unusable. Now the four small yellow squares below the large 4 continually changed and after a few seconds All4 came up. I could easily select a programme and play it. Similarly the My5 player also worked properly.
After 30 minutes the right top of the box was noticeably warmer than the left but so much as to cause me any worries. I don't know how it compares with how hot it got on 1.03.51. I will keep checking to see if it gets hot as some other users have found.