I've struggled with a rounded swing for years with very inconsistent results and a big slice. I started using Daltons technique about 18 months ago. I haven't yet reduced my handicap (12) but I feel much better with the technique. It makes so much sense to me, and I do enjoy Daltons videos - they're really entertaining either though they're a bit dated now. If I could sort out my putting I'm sure I'd be down to 10. I have not been able to master Daltons wristy putting technique - I tried it but couldn't develop any feel for distance.
Im very happy with Daltons method.
I probably should adjust my clubs to make them upright but I haven't bothered.