I find it pretty meaningless because you can literally do nothing (no points, no rebounds, no assists, etc) but if the other team is missing shots and turning it over and your teammates are making shots you can have a phenomenal +/-
Same for when you have a stretch where you play perfect ( your man doesn't score, you make all your shots) but your teammates are putting up bricks and getting blown by, you have a bad +/- even though you played great.
If you look at it from a macro standpoint using an entire season I think it adjusts for all that and might be meaningful, otherwise means very little,
Best stats for me to judge how a center is playing is rebounds and blocks per minutes played and shooting percentage