Well said, Alan. I agree...
When I was young and stupid (I am no longer young), I was riding a bicycle and came to a long downhill (Signal Hill in Los Angeles). I knew I had to "take it easy" on the downhill, but figured that I would simply bring it to a stop if the brakes were struggling, and then walk down.
Of course the brakes were worn and out of adjustment (it had bald tires for the trifecta), so they failed spectacularly, with me picking up speed rapidly. Halfway down the hill was a stoplight that I hoped would cycle enough to turn green before I shot through it. It turned red just before I got there, and one car crossed in front of me just before I shot through behind it. For a brief moment, I pondered the possibility that I should "bail out" and do a stuntman roll onto the asphalt, but by the time I made that calculation?...I was going even faster, and froze.
After I reached a section where the steepness was easing off, I was able to slow down enough to add Flintstone brakes (the soles of my tennis shoes). At least I was wearing a ballcap to protect me from head injuries...(my severe head injuries are from a completely separate incident)
Regen is nice to have, and...if your controller has it, you still don't have to use it, so...I'm thinking you are wondering if it is worth shopping for a DD hub and a controller that has that feature. Like Alan said, it depends on what you are going to do with it.
Pic below is from a long time ago, random grab from the Google.