You take the good with the bad with Cashman. Our problem each year seems to be the rotation, and although it's still too early to say anything about this year's rotation, the early results are not good. He did take steps to address it in the offseason, but given the internal cap constraint he had to make high risk/reward moves rather than just go spending on a FA starter.
I give him credit for acquiring Urshela/Voit/Hicks for basically nothing, which is a third of our starting lineup. Also his bullpen construction is always very good. The lineup is a bit one dimensional but still one of the best in baseball. It's easy to criticize all his failures but I have a hard time envisioning another GM doing a much better job than him.