I like Defcon, myself, but can't compare the two, as I haven't been to HOPE. Maybe I'll check out HOPE when opportunity permits, so that I can give 'experienced' advice on the subject, for next time.
I particularly like the atmosphere at Defcon. While I'd definitely agree with the comment about it being / feeling more like a 'party atmosphere,' at least in my experiences, it seems like the more laid back the folks are, the better networking and discussions I get out of it all, in the end. The sessions are always worthwhile, but the opportunity to chat it up with the other attendees is what I value the most, as I always end up getting more from those opportunities, than I do from sitting through talks. I can't speak for how HOPE caters to that, since I haven't attended, but at least I can explain that as one of the areas I like about Defcon, versus some other events I've been to in the past.
If you do go to HOPE, please drop us some feedback, so I can think on it for next time. Thanks.
~ hayabusa ~
"All men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved." - Sun Tzu, 'The Art of War'
OSCE, OSCP , GPEN, C|EH