I can say about 90% of my DL BE experiences have been extremely positive. Best was last September on DL 134 JFK - OTP and a VERY close second was DL 91 this March from ATL - ICN. Both flights experiences were top notch, and I could really ask for nothing more. ^^

It's strange though, either its a great experience, or it totally sucks. Rarely do I find it "good or average".