I am running Ardour on Ubuntu Studio 15.10 and just installed Ardour 4 last night with the intention of replacing Ardour 3 I had been running previously. I was wondering if there is any need to remove old Ardour 3 files. I was poking through some of my folders last night as well and found some old folders marked Ardour 2 and Ardour 3. Does it make any difference if I keep these or not? I’m mainly asking because I like to keep a clean house, otherwise they aren’t really a nuisance. Thanks!