To access the Multi Pad buttons, you have to lift your hand, true, it may be your left hand or your right hand, depending on your needs. There may be no general answer which location is the best.
Personally I find myself more busy with the right hand, so I liked the Multi Pads on the left side. Actually I really had to rework some songs to find a new solution how I could achieve what I'm after, because I had only a very short time window to hit a Multi Pad button with my left hand, and it was impossible to do that with the Genos having the Multi Pads at the right side.
If you look at the left side of Genos you see it's crowded, because the sliders and knobs need much space. But certainly it is the right place for those controls. So the Multi Pad buttons just had to move. The ideal position for me would be above the registration, but that would have other drawbacks so I would not opt for that.
I can get along with the new layout but I'd really like to see the Multi-Pad buttons swap the place with the OTS buttons, so they move more to the center to be more accessible to the left hand. I admit that I don't use the OTS buttons when playing live anyway.