I agree, honestly the standard controller is really the best option overall for the Intellivision. If you can't deal with them, then the system probably just isn't for you.
IMO the fundamental problem with the Intellivision controller isn't the disc at all, anyway. It's simply an awkward design overall. The impression it gives is that it was designed to look good and fit into the console first, and then actually work second. The most glaring problem to me is the tiny, mushy fire buttons that are practically recessed into the sides of the controller. And I'm essentially convinced that there is no good way to integrate a keypad into a game controller, but I won't fault Mattel for that since they were among the first to even try it.
The Intellivision II controller is often criticized but I actually prefer it since it feels a little more substantial (at least on the edges; the middle is still hollowed out to allow the cord to tuck under it when stowed in the console), the "fire buttons" (which actually aren't buttons at all but rather touch-sensitive nubs) are sensitive and easier to actuate, and I have to look down at the keypad even with the System I/III/Super Pro's bubble keypad, so the Intellivision II's flat keypad is a non-issue for me.
Essentially, no joystick upgrades or disc replacements actually address what, to me, are the real problems with the controller. And the Wico is actually worse.