As far as the conversation about Hermsen is concerned, I see him making it. I look at him and see a future Nick Blackburn, which will have a place as a future Twins #5/#6 starter (I am optimistic future starting rotations are going to be better than current...a few years out, please!).
As for who is the best rotation, my vote goes to New Britain. Andrew Albers is going to have a very good year and Luke French will be awesome in AA, assuming he stays there awhile. All fans and the Twins need Wimmers to be what Hendriks was a year ago. Hirschfeld will be what he was last year, a solid innings eater. To be the top rotation, they need Darnell to pitch as well or better at AA as he did at Fort Myers last summer.
The surprise at Beloit will be Gruver, who I think will be very good. I don't know how long Summers will stay in the rotation, but if he does, I rate the three draft picks from last year, Boer, Summers and Gruver, as very, very good.