When you say it plays 4 way like a 4 way and 8 like an 8 - is that from experience?
Yes.
I have both Happ/Midway and Williams 49-ways, as well as a BUNCH of other sticks.
I prefer the Williams ones to the Happ ones, because they have more resistance to them.
That said, I don't use them as 8-ways or 4-ways very often.
I have 8-ways and 4-ways to use.
The 49-ways FUNCTION just like 4-way (with the GGG interface), but they don't FEEL just like a 4-way.
They do FUNCTION and FEEL like a round-restricted 8-way, in 8-way mode, however.
ANY round-restricted 8-way will not play 4-way games well.
This includes Wico, P-360s, Supers, etc...
There are only two ways that the 8-way data can be interpolated down to 4-way data.
The first is to ignore any diagonal, and just wait until the stick comes back to a true direction.
This creates HUGE dead spots in the diagonals.
The second is for the software to GUESS which direction you meant to go when you went into the diagonal area, and send that signal until you get out of the diagonal.
That means that if you go from Right to Up-Right to Up, the software will either keep sending Right until you get to Up only, or will send Up immediately when you hit Up-Right.
Both of these methods will frustrate you to no end with improper signals.
Truthfully, based on your other comments, it sounds like you are not going to be happy with ANY of the "one stick does all" solutions.
There will always be something that doesn't feel right.
You should give serious consideration to a modular system.
That was the only thing that actually satisfied me.
You ALWAYS have the right stick for EVERY game that way.
Nothing else compares to it.