Nothing wrong with the more recent lightly sprung Gibson ones, I use them all the time. The secret is a very light flexible wire so the plungers are free to ‘follow’ the wheel rim. Kean ones are as has been said very fiddly and too stiff.
Highlevel D10 with Gibson plungers, runs beautifully.
Plunger pickups seem to be a bit like Marmite, I love them and must have fitted dozens of them.