So,Degenkolb isn't that good according to some yet the real view of a rider I like to hear about is from the experts,i.e. the top riders in the peloton themselves,Cavendish has described Degenkolb as "pure class" (source:Cavendish's twitter account).
He may not win MSR but he can win GT stages against the best and not just in the Vuelta,he's won at the Giro,placed high in classics before,4th in the Worlds,quality rider who should not be dismissed readily.He has a classic in him at some point for sure.
He's also a decent guy and a good teammate which are other reasons for liking him.