I couldn't tell you, but I can tell you it is easy to find out if you are building it yourself. I really like crossfeed, so chalk one up for the Meier crossfeed -- however, you can always build a separate passive crossfeed unit later if you want. Since the 495s have an impedance of 32 ohms it would seem that the 47 mod would be great for them. Why not just do both? You don't have to use the Hansen board you know.
The default circuit of a cmoy with crossfeed (i.e. the complete Levallois circuit) has more gain than the default Apheared 47. Apheared designed his amp for more current than the cmoy though, so his gain is only set to ~3, while the default Levallois has a gain of 11. But as JMT said, you can change the 2 resistors (resistor in the feedback, and resistor grounding the inverting input -) to adjust the gain.