Especially RCP, given that they purport to be a serious outfit and have (despite having conservative political leanings) purportedly serious people running it.
Even in this cycle I would look at them based on their track record. But I said it before the election: some of the decisions that they made, about which polls they would include, but also in how they rated races (ie. tossup, leaning states, etc.), how they deducted poll margin based on previous cycle misses, how they made projections that didn't even match their average (Michigan Gov for example).... these were all decisions that were, sooner or later, bound to backfire.
The polling industry in and of itself has, and continues to have, problems.... but elaborately unskewing polls doesn't work either. It didn't in 2012, nor did it this cycle.