Your story sounds exactly like mine Larry. I learned from Steve Kauffman too, I still have my VHS tapes. It seemed like it took a long time to get the feel of keeping the DUD's going through crosspicking, but suddenly one day it just felt right and trying to do anything different felt awkward.
For the past year I've been working on DDU's and it's taking longer than learning SK's teachings. I guess you get used to something, but it is working. I find myself naturally without thinking about it doing the DDU method at times and they both are feeling natural. At faster tempos I still struggle some with the DDU and want to go back to the DUD.
For me, it seems to be helping my playing considerably learning both. I'm sure some would argue that and that's ok, but we have to find what works for us as individual players. I started very, very slow in trying to learn the DDU's and like I said, I still struggle at faster speeds but it's coming.
Check out Bryan Sutton's Secrets For Successful Flatpicking DVD. He's light years beyond anything I can do, but there are some good tips and tricks in it that are helpful. I didn't get a whole alot out of it overall, but some things in it are helpful. If you want, I can send it to you for as long as you like. If anything, it's a good dvd just to watch his playing. Cody Kilby's in it too.
I think it's worth the effort, but it takes alot of time and patience. Just be careful that it doesn't take away from what you've already accomplished, anything that does that should probably be shunned. I try to learn new things while still practicing the old (as long as it's something good and not a bad habit).