The dispersion of the 3cm auto-cannon was nerfed in 1.10. Now I find it is hard to be effective with it at anything but close range. It wasn't great at engagements over 200 m before but I think it became noticeably worse with the patch.
As far as I know the L/60 wasn't changed. After playing a few times with each I think I prefer the L/60 as it has better accuracy and doesn't have the long clip-reload. The downsides with the 5cm are that the penetration is quite bad unless you are shooting APCR and that the auto-cannon can be more fun to use.
I used to play the Luchs as a relax tank when on a loosing streak and enjoyed the hit and run play-style with the auto-cannon. Even though the auto-cannon is nerfed I think I want to keep playing it occasionally it as it stills seems like a quite good scout tank with some sentimental value to me.
So I'm wondering if you have switched to the 5cm L/60 or if you still play using the 3cm. Would also be nice if you could explain your reasoning.