Now Life's End I can totally get behind. That mod inspired me so much to make a mod of my own back in the day. Naturally I was nowhere near talented enough to complete and upload anything of worth, but I would like to return to something like that in future, set in Black Mesa but maybe a little more tongue-in-cheek that The Core is going to wind up.
Azure Sheep though... I dunno. It was certainly never one of my favourites. The only thing I can say that's remotely positive is that it's long. However, I feel it's only long because of how padded it is with countless hallways or maze like areas. Yes, some of it looks great but there are a lot of sections that don't.
I've also never played a DAV level, even to this day. I think I got one or two on a PC Gamer CD back in the day, but for some reason I never got them to work.