I've had mine for more years than I care to remember and still ride it. Longest trip was from Lancashire to the D-Day celebrations in Normandy in 2004. Despite the fearsome hot weather it never let me down. I agree that everything Kewelde says about riding. The girder forks and solid rear end means you have to concentrate on your riding style.
Here's me trundling through the Normandy beaches on my way to Gold Beach and Ver-sur-Mer.
As to your comments about a 'designed' DR bike ... it wasn't. It was a simple civvie bike which partly fulfilled the Ministry's desire to get something which would tide them over until they could find something better and given that BSA could produce large quantities quickly it was adopted. In fact the first time the bike was put forward for consideration in 1937 it was rejected as exhibiting too much wear of components.
In their second trial they were still only assessed as 'fair'.
Amazing to think they carried on in British service into the 60's and there were apparently some still lurking around in the early 1970's!
I have had to rebuild my gearbox as it was a bit graunchy but thats the only beef in over 6,000 miles.