Batchworth Heath from Rickmansworth

I only have experience of this climb during quiet periods - firstly during the Covid period when there was very little traffic on the roads, and lately in the very early morning, before the traffic gets going, so I can only speak for my experiences at those times. During Covid I rode up it and then round by Ruislip Lido, and that might still be a viable route on a ride for pleasure, but the busyness of the roads puts me off. These days, I only use this road as a means of getting in and out of London, I wouldn't think of using it on a ride for pleasure. Sometimes I dip inside the M25, but I'd generally be looping through Harefield and back via Maple Cross or Denham.
Taken on its merits it's a good climb, with a steep lower section and quite a lot of greenery higher up. When you do get cars they tend to be travelling quite fast, but the road is wide enough for them to pass even when traffic is coming the other way. The pedestrian islands can be a bottleneck though.
So, taken on its own, the climb is worth doing, but you'd need to have a good reason for going up it.