4.1 is considered probably the most stable (at least the last stable version anyway). Like Luigi says above, 4.2/3 were just made to block and remove HBC. I've been on 4.1 since I modded in 2009....no probs whatsoever with anything.
just do a Syscheck, using Syscheck GX (ModMii, Download Page 2) and update your IOSes, cIOS, cMIOS and whatever else using the ModMii Syscheck update wizard. you'll need syscheck.csv from the root of your sd card.
if you want to stay on sm4.1, don't install either ios70(ios60) and ios80(ios60) or sm4.3 (which will be called systemmenu_4.3U_vXXX)
understood but i had wii game launching problems when i was 4.1. i was trying to load a wii game from USB (backup mind you) and the game never loads.
I had heard some rumors that 4.3 introduced USB 2.0 so faster wii game speed and when i was on 4.3 wii games did work!!
I will stay on 4.1 however i have Just one little question. I am geting a 16gb sdcard so i can put wii games on it. but if i put the sd card on WBFS mode will it be read by the wii??