I run a number of Wii’s on only System Menu 4.1 and have found zero disadvatage to using 4.1 (or conversely no advantage to System Menu 4.2 or 4.3). Actually as part of Wiihacks.com they recommend everyone to downgrade there System Menu to 4.1
Remember if you ever actually do a System Menu upgrade to like 4.2 it MUST be done manually using a wad manager (like MMM) and not done only with Nintendo. Otherwise Nintendo’s update will nuke your softmod.
I would just resoftmod your Wii from cradle to grave using Maui’s lastest “Hack and Wii” manual on Wiihacks.com and be done with it. And I would stick with (downgrade) to System Menu 4.1 . It’s just a small pile of wads to install to downgrade, takes 3 minutes, that’s all 🙂