Value of upgrade - my thoughts after almost two months  

Value of upgrade - my thoughts after almost two months

A few thoughts on my MK4S upgrade experience, FWIW

1.  The upgrade was fully worth it for the new blower, which looks ugly, and blocks the view of the nozzle, but performs great.  I can ignore most Prusaslicer warnings about bridges and angles, and my prints turn out just fine. Sometimes, I ignore them even at the most extreme, and the print might have a slight imperfection, but is always serviceable.  Prusa Did what it claimed in that respect.

2.  I also think the replacement of the Y-Axis tensioner and holder was a good move.  If there was a chance the original parts would start to deform and bring the Y-Axis out of spec, then it would cause unusual print problems that might be hard to diagnose.  I believe this because my MK4S replacement parts didn't work right, either from my own failure to do something right, or (see below) because they were defective prints.  In any case, I was unable to tension the Y-Axis quite right after I put in my upgraded parts, and this caused all sorts of print failure and strong ghosting on printed letters until I ordered replacements and installed them.  After that, appropriate belt settings were achievable, and the printer is printing beautifully again.

3.  My fan case was bad as received, and the holes in it did not line up at all.  So much so, that trying to fit that case on resulted in stress on the case that slight deformed it.  I finally realized something was not right, printed a new case out of PETG from the online files, and it was perfectly aligned with the holes on the metal frame.  I was able to prove to Prusa that this print was bad by sending pictures (but I'm sad my word was not taken for this cheap part), and another is on the way.  As I said above, if the Y-Axis holder and tensioner were printed on the same Prusa factory printer, it may have also been the reason for the failure of those parts. No way to know however.

4.  I cannot comment on the WIFI or NFC upgrades.  I did them, but I haven't used the NFC at all, and have not noticed any other differences.

5.  The High-Flow Nozzle did not do anything for me that I could see, and I switched back to my .04 Diamondback, which prints more cleanly in my opinion.  I never saw significant time savings with the HF nozzle.

All told, I don't regret the upgrade, and would have paid the same just for the increased fan efficiency and ability to print without supports on many prints where it would have been needed before.  These are my thoughts and opinions, yours may be different, but I'm happy with the MK4S conversion, and am very happy Prusa has this option for its owners.

Regards.