I think both Jeff and Derek have good points and both are right.
I can say that I could never get my DR to run well shimming the stock needle with any combination of jetting.
Sure, it ran, but I knew it wasn't it's best. But I think Derek was always talking about a NON USA OEM. These have notches ... unlike USA needle which are non adjustable. I think Derek also mentioned a few KTM needles as perhaps being a good fit to the DR.
The DJ needle has (for me) made a huge difference overall. I'm sure there are better needles ... and since my DJ needle now has about 35,000 miles on it, I'd be happy to try something else. My bike has never been dyno'd so all my assessments are "seat of the pants".
Derek, I'm in the Bay area ... if you can recommend a better needle I could buy ... I would try it out.
I can see some slight wear on my current DJ needle, but bike still runs strong; starts, idles well, around 50 MPG, 102 MPH (measured) top speed (prone) and power wheelies in 2nd gear ... no clutch.
155 main, stock Pilot, open air box top, Twin Air, stock muffler, 1/2 turn out on fuel/air screw, no header weld grind .... 50,000 miles. Throttle response on my bike could be crisper ... but not sure the DR motor is really ever a "crisp" revver. It's no Triumph Daytona after all.