I left my Humax 1000S recording unattended and in standby for one month, it did not miss a single recording. I have settings of auto on/off and padding of 2 min start / 10 min end.
Having said that I am not 100% happy with the box which is liberally scattered with bugs and stupid omissions, due I think to design by committee with no single overseeing responsibility. Hopefully, given the level of dissatisfaction being openly expressed on the Freesat forum, this will get fixed.
Hmm! I own a Panny DVDR which is now 3 years old and that just works and always has, never known a recording failure in all that time. It is a rarity for my Sky+HD to miss a recording too. I want a set and forget product not one where you have to add padding to recordings. A good efficient EPG. should take care of this.