With padding, you get conflicts if you try to record two back-to-back programmes on the same channel because the bits of padding overlap - and it says it can't do it. I seem to recall that what it actually does is to carry on recording the first programme through the padding period, and then starts the second programme late. It has, of course, recorded both programmes - but the start of the second one is in the wrong file!
So my conclusion is that the disavantages of padding outweigh the advantages.
WT
Are you sure this is the case WT? Over on the Hummy.TV forum (am I allowed to mention that here? ) I found this in the Wiki:
"Note :- The Humax can't record the same channel at the same time twice, Even if there is a free tuner, So padding between consecutive programs on the same channel will be turned off and EPG times will be used."
That seems to suggest that padding might be the safer option.