My son and I have a Monoprice Maker Select Plus and it's been great after two specific upgrades. We replaced the carriage plate with a heavy duty one which made bed leveling so much easier, and added z-axis stabilizers, also contributing to better bed leveling and also overall print quality.
We've also replaced the hot end with an all metal one from Micro Swiss, but that was just so that we could use more exotic filaments like glow-in-the-dark.
As has been said, a lot of it comes down to the quality of the filament used... Hatchbox has been our "premium" filament and Inland our close second.
I'm craving for a Prusa printer but only because it does auto-bed leveling (bed leveling is, arguably, the most tedious but necessary part of printing).
None of the printer really needed adjusting (beyond bed leveling), but a lot of tweaks in the slicer software was necessary to get optimum prints... I used a x-y-z calibration cube model and made one parameter change at a time and printed a new cube. It took the better part of a Saturday afternoon but prints are at high quality now.