You don't need much acceleration to generate the somatogravic illusion. As it's pure geometry it can be calculated. An acceleration of 30kts over a period of 10 seconds is equivalent to 1.54m/sē, which translates into a perceived pitch up of 9°. As many aircraft climb at a lesser angle than this, the aircraft can conceivably enter a descent if the illusion is not correctly countered.
This means that pilots of low powered GA aircraft are just as susceptable as jet pilots. And the staistice reflect this. Somatogravic illusion accidents either tend to occur during go-arounds for airliners, but GA aricraft it's usually on take off at night in VMC at airfields in spasrely populated areas where there are few visual clues.