The P70 doesn't have accompaniment.It also doesn't have as many sounds.
They are different products for different markets.
You may find a lighter weighted action,but it won't have the quality of Yamaha's GH (Graded Hammer)which is considered the best by many pros.

Ian
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Yamaha Tyros4, Yamaha MS-60S Powered Monitors(2), Yamaha CS-01, Yamaha TQ-5, Yamaha PSR-S775.