midi keyboard with heaviest keys

most weight in the keys

Definitely not the MPK-49 then.

I use a korg sp-250 digital piano when I want a piano feel, and a micro-x or R3 when I want a synth feel. Any keyboard with MIDI jacks (or often USB midi) can be used as a MIDI controller. I got keyboards with sounds, so I never saw much draw for a single-purpose controller keyboard.

Ronald wrote:most weight in the keys

Any midi keyboard which claims to have fully weighted keys should feel similar to a piano when played.

Many synths and midi controllers (albeit the larger 88 keys versions) have weighted keys for the benefit of trained pianists.

Why is the 'most weight' even relevant?