Although I have never manhandled a PD. I understand their reputation for snapping cranks lays behind them having a dry sump. Relying on oil feed pipes to relay lubricant to journals et al can be a risky hobby.
The benefit against HA's wet sump is quicker to pile on the revs as the moving parts aren't thrashing around in gallons of Goo.
However if the vibrations loosen off a feed pipe, then the first you'll know about is "Bang Blast!"
And, as previously discussed (albeit years ago) remove the cylinder heads off most 2 cylinder engines and you'll find the pistons at the same position. That is to say while one is approaching compression the other is approach exhaust. While on Lister one will be up and the other down, so one lung is half a cycle behind the other, making for much easier hand cranking and starting.