Hey Bob; I am pretty much in the same category as you claim to be as far as dirt riding experience. I recently bought a an '09 KLX250S and I'm very happy with it. By the way , I am 71 YO. I don't do any single track but mostly gravel and back roads. I owned a DRZ400S a couple of years ago and for me this bike is much more enjoyable. Acceleration is leisurely so say the least but you can cruise at 60 to 65 without too much strain. Just don't plan on any interstate riding or passing many other vehicles. I ended up lowering the DRZ but at 5'10, the stock seat height on the KLX is very manageable.
It will be interesting to see how the new 250 Honda compares but if you want to start enjoying DS riding before Fall, i think you would be very happy withe the KLX.