I really can't believe you're trying to say that a body which gives a person in Wyoming 50 times the voting power of a Californian leaves us "to the will of the popular vote". There's absolutely no reason that legislatures electing senators would lead to "more stability" or whatever other nonsense you made up. The only likely effect would be that people would start voting for their state legislature based on what senator they promised to put in office.
i disagree, it will still be partisan and people will likely vote for the candidate of their party
having said that, my hope would be to remove some of the big money spent on senate races and make the selection more a reflection of the political makeup of the state