Other things to consider:
Even though new hires aren't sitting reserve for very long, at some point you will upgrade and you will sit for years on reserve as a Captain. SkyWest reserve is a unique kind of hell that has no real description. On reserve at SkyWest, you will be treated on a sub human scale. Of all the people that I've run into that left SkyWest for a total different career left because of the way they were treated by SkyWest on reserve. If you come here consider yourself warned.
Training failures, have been mounting and are climbing higher, as a percetage. There has been a total turn over of training department management and there is little room for issues. Many new ground and sim instructors that have zilch experience. Lots of new LCA's again with little experience. Until you have finished your IOE your CP cannot help you, you are at the mercy of some new training department micro manager that is out to make a name for themselves.
If I was in your position, flow would have a lot of weight in my decision.
The upgrade at SkyWest is at least 3 years and things could change over night and come to a grinding halt.
There is no way I could bunk up with another person for 2 months, SkyWest only offers rooms with 2 guys in them, nice way to start your "first class career"!
I'm senior SkyWest, I would go Compass, Envoy, Republic in that order.