Here is my feed back in case someone decides to go for a midi controller. I'll try to make it as short as possible.
I got my self the Korg microkey2 61. The keys size is small but since I didn't play piano before they are just fine for me. I have regular hands. rather small than big. They are semi-weighted as advertised and to me have a greet feeling and definitely do not look or feel cheap.
The korg bundle that comes with it is useless at least for me. The Korg M1 Le has only 2 acoustic piano voices that are probably not sampled.
I downloaded a free DAW - MU-lab - it has a low CPU usage, it's free and accepts vst plugins.
I previously tried lmms by linux, it has a high CPU usage and will hang while playing.
I use the DAW for the Piano VST plugins available out there. I downloaded a few free VST piano plugins. Keyzone and 4front piano have realistic piano sounds and are light on cpu.
If you feel that your keyboard is not responding correctly. it's not the keyboard, it will be the DAW or the plugin that are using too much CPU.
for example 4front (that is a very light), if you use the metronome with it, you'll feel your keyboard slowing on the response.
That's probably because I only have 2 GB ram of memory.
Just as a note, if you download a daw or a standalone vst, you might face a sound problem on your windows. Just download the driver software from site.
I am now finally learning to play the piano, using Alfred's adult method and I am quite satisfied with the outcome.