Well the adapter (actually two of them) arrived yesterday, and all I can say is WOW! A 510 atty on a KR808D-1 batt is an IDEAL combination! Bigger, smoother hits, and considerably more milage.
I bought the KR808D-1 kit for my wife, but she didn't care for it. I tried selling the stuff on the classifieds, but (fortunately for me) nobody bought it. As a last resort, I thought I'd look for an adapter so I could use the batts with my 510.
Now I think I'm going to relegate the 510 batts to backup status.
And I can't say enough about NHaler. I ordered just one adapter and two sample
juice bottles on Sunday, and they were in my mailbox on Wednesday. Plus, he
threw in a second adapter! So I was able to build a KR808D-1/510 hybrid for my wife as well, and she likes it much better.