I have a Yamaha SR400. It's a fuel injected thumper oriented to riding on the street. 66 MPG with regular gas. Kick-start only with a decompression lever. Not quite as finicky to start as my old BSA 500. Lower compression and less horsepower than the BSA. The DR400 package that I admire most is the super-moto. I might have gone that way, but my Versys with 17 inch wheels front/rear fits that niche just fine. I went with the bush pig to have a dual sport that can work competently on the street or dirt. The other bikes in the garage are really street bikes.
I really admire the hot 450 singles, but the seat height is out of range for a 30" inseam. Besides, I might forget I'm 65 and do some things on a motocross track that aren't age appropriate :-). The DRZ400 is a sweet bike. It will treat you well.