My slap happy weedwackers have arrived and I've put them on the bass, which was a much more fiddly affair than I expected. I haven't tried it amplified yet, but I love the blurry sound. I can achieve a nice bit of rockabilly slap, which I was never able to do with the spirocore weichs.
I'll see how they go. I doubt I'll be going back to the spiros, but may upgrade to a set of Lamberts in the future. I wonder what the going rate for a used, but hardly played, set of spiro weich is