There is no reason not to upgrade to 4.1
On the Minelab side, everyone complains that the CTX has a way to update but they never release updates.
On the XP side, they release updates and many seem to be hesitant to upgrade.
Software updates are released to fix bugs, accommodate new accessories and features, and improve functionality.
Reasons why people don't upgrade:
1) Don't want to be the first to try an unknown release?
2) Theirs is working fine, so no need?
3) Lose features they like?
4) Have to relearn if changes made?
But bottom line is you lose nothing and gain some. What you gain may not be important to you, but you may also gain in areas you're not aware of.
And if you ever have any problems, manufacturer will typically ask that you be running the latest software first, as that may have fixed bugs.
So you don't have to be the first to upgrade, but I see no downside to moving to 4.1. Certainly nothing to worry about in your case if you have to.