I am sitting here after filling a few on-line store orders for my customers. I am watching "MamaCetus" (My 3D Cetus (brand) printer doing her thing. She's very slow because that IS her thing, using only 150 micron layer height. BUT she is producing outstanding 3D printing.

I do almost all my printing these days at 150 microns. Sometimes I drop to 100 microns. The penalty is very long print times. The reward is very nice looking prints.

When I started printing several years ago, I thought 300 microns was the normal height to print. (it was...) I considered 200 microns a venture into extreme printing. I thought 100 and 150 micron layers were impossible territory. Boy, was I wrong..

At the time the written consensus was speed was the important criteria to being a good to great 3D print machine and printer person. Boy!, was I wrong again.

Speed kills. In automobiles and 3D printing. Good printing is not about how fast you do it. It is how well you do it... Sound familiar? Ha!

There are certain physical requirements (physics) to FDM style printing. Feeding filament, melting it to a precise (nearly precise) temperature, Forcing it to flow from a very small orifice at a pressure reasonable for the feed system, move the print head in 2.5 dimensions, starting and stopping at very precise measurements of distance while obeying the absolute laws of mass and inertia. Cooling melted "squished down" plastic but having it bond securely to the layers below and along side. It's watching a 3 ring circus in every ring at once. (Probably never experienced by most readers here.)

In reality, there is a not-to-exceed point for travel speed in 3D printing. 

My wife is a piano music teacher. I have countless times experienced a new student, who has learned the sequence of notes in a music piece, play the piece many times faster that it was ever intended to be played. In today's culture, faster is better because it proves you know the notes. Yeah, it proves you know the sequence of the notes, It, however totally destroys the beauty of the music. Eventually they learn they are not playing notes, they are playing beautiful music, where correct speed is a critical ingredient to musical success (and pleasing the teacher...)

Great 3d Printing requires slowing down to enjoy the music.