<p>I currently print with a .4mm nozzle on my extruder, and my prints seem to come out fairly accurate; would I see much of a difference if I went to a .3mm?</p>

<p>What are the pros and cons of larger and smaller nozzle sizes?</p>

My understanding is that the only difference is your range that your layer height can be. For example, the optimal layer heights for a 0.4mm nozzle fall between 0.1-0.3mm. So, we can assume a smaller nozzle will yield a lower range. Keep in mind that varying sizes in the nozzle could produce complications more prominently than with a standard size. Things such as ooze, clogging, and filament backup may occur with a smaller nozzle size if your slicing engine is not setup correctly.