I must be the odd one in the bunch.
I don't tone unless the print needs it. My understanding is that archival property of the selenium toner is dependent upon the degree of toning. That would mean lightly selenium toned prints have very little protection. Conversely, to get a worthwhile protection, I have to tone it to the point the color change will be obvious. I happen to like the result I get from MGIV.
So far, I played around with Selenium, two bath sepia, and brown. I use all of them occasionally but not as a rule.
I use StabAG for print protection if I think the print is worth preserving.