Steve McIntyre writes:
In the context of IPCC SOD FIgure 1.5 (or similar comparison of models and observations), CW13 is slightly warmer than HadCRUT4 but the difference is small relative to the discrepancy between models and observations; the CW13 variation is also outside the Figure 1.5 envelope.
Next, here is a simple plot showing the difference between the CW13 hybrid and HadCRUT 4. Up to the end of 2005, there was a zero trend between the two; the difference has arisen entirely since 2005.
See more here: