If +1’s, comments and shares is not enough for your, here’s another metric to check for your posts. If you added a photo with your post, in the full view of the photo click the “Photo details” heading. It will show various information about the photo (dimensions, your camera, etc) and also the number of views, e.g. how many times the photo has been displayed in a stream or your profile)
Jari Huomo has actually put up a page (replace the number with your G+ ID) where you can see your photo-posts sorted by views but unfortunately you do not see the actual number.