I'm with you. The Merkur HD with Derby blades is a great combination. I've tried Merkur & Feather blades, but Derby performs so well in this razor.
If I have to properly enjoy myself, then straight shaving is great. If I'm in a hurry it's DE only. If I'm going for ultra BBS, then straight & DE shaving. Some of the hair on my neck grows at a bad angle, and I can't get a true ATG pass with a straight.