I'd say I'm about 85% private, 15% public. I'm not in any of the top-tier trackers so there are times when I'm looking for something obscure and won't find it on my few PTs, so off to the publics I go. Last night I found a DVDRip of an 80s show on TPB that I liked better (slightly better color quality) than the single WEBDL on TL. That doesn't happen often, but it happens.
My favorite tracker is CRT. Cozy, and I love older media.