I’ve been printing for several years now and am constantly trying learn more and improve my quality and speed. I have owned Qidi, Creality, Anycubic, and Bambu printers and done basic maintanence repairs to complete rebuilds on some of them. My two E3pro printers are my most reliable workhorses as they have been giving consistent prints for a couple years although they max at around 60-80mm/sec for quality prints of PLA. They have stock marlin firmware, dual Z, 4.2.7 boards, and one has a BLTouch and Bowden tube setup, the other is using a sprite pro extruder without auto leveling. I was able to get a couple E5+ printers at a steal knowing they would take some work to get going and was able to make my money back on selling the one that I kept stock but got running well. The one I kept has a silent 4.2.2 board and a Biqu H2 extruder. I’m waiting on the delivery of a sonic pad to convert the printer over to kipper. I know that I will get better speed and higher quality prints from this upgrade, but am curious if further tinkering would be worth the effort. I figured I would start up a discussion to see how many on here have done similar upgrades and see what kind of improvements can be gained to gauge how much further I take these printers instead of just selling and purchasing more of the newer technologies.