YouView Box very slow since update

Switched on my 2 years old Humax YouView Box today for the first time in a week.  Couldn't watch immediately as it told me it had been updated, and then proceeded to give me what amounted to a nearly 3 minute commercial which I couldn't seem to cancel.

Now the box it VERY much slower to respond.  They've changed the display, which now seems to think its on BT TV (it isn't, and AFAIK never has been!).  The interface now uses pictures rather than lists in MyView (now renamed MyTV for some reason), and is IMO much less intuitive to use.  NOT an improvement.  Alas, there seems to be no way to change the graphical interface for recordings back to the old text based one, and no way of rolling back the 'update'

Been on t'interweb, and this seems to be a general problem with 'older' YouView recorders (mine's only 2 years old!), as they are updating software for HTML5 (whatever that means).  Probably just a way of trying to make us buy new hardware (he says cynically)

Funnily enough, SWMBO's YouView, which is identical to mine apart from a larger hard disc, hasn't updated.  Hope it doesn't, or she'll be moaning continuously about it and somehow it will all be my fault (sigh)