He has problems with focus, intensity, positioning and consistency. Not good if you intend to be a strong NHL goalie. There is absolutely zero negative impact if you go out and get either a true #1 or a young competitor for the #1 job this offseason.
To me this is the most frustrating thing about Dubnyk. He has all the talent in he world but until he fixes major structural flaws in his game he will never be a first string goalie.
It seems clear that he got through his minor hockey and junior career relying on his size and quickness without ever developing strong fundamentals. He loses his angles in traffic and plays so deep in his net that he is incredibly susceptible to letting in shots from the high slot and blue line.
On the plus side it's nothing coaching, hard work, and practice can't fix. On the minus side if Dubnyk were willing to put that type of work into his game we wouldn't be having this discussion in the first place.