I enjoyed my BSA 500cc single. A wonderful thumper. Mine was offroad only. Today, my thumpers include a Yamaha SR400 (fuel injected, street legal) and a Suzuki DR650SE dual sport. The SR400 is kickstart only like the BSA 500. It takes a little coordination with the compression release and kickstart to turn it over. The DR650SE is back in the garage as I love the electric start (auto compression release) and the ability to take the "bush pig" offroad.
While living in San Diego, I seriously entertained a Zero motorcycle. It would have been perfectly fine as my daily commute with a 15 mile round trip on surface streets. It was not well suited to the 1300 miles per month that I accrued on the freeways. The Zero lost out to a Kawasaki Versys, Harley XL1200R Sportster and Harley FXDF Fat Bob.