Some of that is due to the rolled-off sub-bass on a lot of dynamics, and the consequent mid-bass emphasis. Another factor is, indeed, the amplification. If you use amps designed by people who have made speaker amps in the past, they tend to make better headphone amps, which, for example, increase in power output as the impedance of the headphones drops. A lot of headphone amps lose power as the impedance goes down, especially portable gear, which will have power supply limitations.I believe Dynamic drivers slam harder than planars in general. I have shared my observations when we launch the LIRIC (HERE). In my experience, the LIRIC is one of the more energetic planar and you make it as impactful as a lot of dynamic drivers, but you need a headphone amplifier that offers strong output power with excellent control, low output impedance / high damping factor.
I mention this as I was comparing the Liric out of the W2-131 and RU-6, with the extra power available in the RU-6 giving very noticeably better dynamics. The thing I like about them is that they sound great out of even basic portable gear, yet will scale up to the TT2 and the like, especially with a better-than-stock cable. Now...if only they folded!