I've been using private trackers for the past 16 years. I've never gotten any notices from my ISP, or been involved in any legal related issues since a lot of those sites have now been raided or shut down. The only time I use a VPN is for anything public tracker related. Obviously a VPN is good practice but I haven't seen the need for it since a lot of trackers require you to sign up with your home IP address anyways.

Edit: Forgot to mention that my downloads are about a 50/50 split between downloading locally and on my seedbox.