I don't enjoy it either. The tampering of the scrollbar and having the text stuffed into some sort of frame ruins the experience. Those two problems make it difficult to read on G+ so I usually just avoid it.

At first I thought this would just be an easy CSS fix, and it almost is -- but the reason this problem exists is because they put that huge sidebar at the top of the page with the guy's face and four or five links under it.

Seeing as long posts and discussions are starting to become pretty common on G+ I hope that the G+ team invests some time into figuring out how to make everything more readable.