Find a place to test several keyboards. After some "research", you can test DPs instead of pure MIDI output devices. Simpler to test and normally you can find a DP with the same action as targeted controller.
There are several producers: Fatar, Roland, Yamaha, Kawai, Korg, Casio and PRC native producer known under many names. Most (all?) devices from respectful companies not int hat list (f.e. NI) use Fatar. "No name" sometimes use entry level Fatar, sometimes PRC native keys.
Each producer has several action types (all have lightweight", "normal" and "with wood", Yamaha and Kawai have models with real instrument mechanic). All of them are different (toward to the "top end", own piano skills required to notice that difference). There is no universally the best action. F.e. technically the best Kawai VPC1 (real mechanic) is still typical Kawai action (in "lightness" and the shape), which some people can find worse then less realistic but more "heavy" and traditional in shape Yamaha "normal / with wood" actions.
But with exception of "no go" actions (f.e. M-Audio Keystation Pro, PRC native and some entry level Fatar), I do not think the difference for not pure piano music (just occasional melody/chords/arpeggio) can justify a dedicated piano controller. Good synth actions (without hammer mechanic) can produce reasonable results with a piano VST, while are simpler to use for all other instruments. The key point is how good particular person can keep the velocity on particular device under control. That is the person specific, even for devices which technically allow that (most controllers from known producers).