I mostly agree with you here.
You hit the nail on the head with the whole noodling around for hours problem, which is what this album itself spawned. On its own merit, I will give that A Go Go is not the worst album I have ever heard, but when I discovered it I was coming back to it from being a fan of other stuff these artists had put out and I found it comparatively boring.
And my complaint against this album, beyond not being what I think it could have been, is once again local. These tunes were the basis for more than half of the bands I encountered around here for a long time, and it was painful to listen to, as it was obvious that the extent of their "research" was this album. No harmonic or rhythmic exploration beyond this, completely ignoring the history of what jazz, funk, or whatever you would call this was built on. Just background noise for people who wanted to "support live music," but more realistically wanted to be stoned off their balls and silence was not an option. It was safe, unintrusive music played by people who believed that this was as far as music should go because they were too lazy to practice anything beyond a simple chord/rhythmic motif.
While I don't believe that A Go Go was designed with that purpose, wayyyyyyyyy too many people have seen it as an end and not a beginning, and that's my overall issue: too many times I have seen the lowest common denominators of this album championed as the pinnacle of where music can go, and I couldn't disagree more.
As far as Scofield doing this "jamming" sound, I would much prefer Uberjam as a start. The songs are more realized and fleshed-out, and his playing is... well, it sounds like HIM. There's still the one-chord exploration, but it breaks beyond simply a groove and plays heavily with rhythmic comping across the instruments, especially live.
[For the record, no pun intended, I would rather listen to Rough House, Bar Talk, Flat Out, or I Can See Your House From Here.]