I think the MLS has better players, but the Primera League is probably better coached. Any match between clubs from those leagues would be Championship quality and in fact both leagues have much the same problems, regular fumbled passes, players trying skills and tricks for no reason, average ball control, major gaps in quality through a squad, etc.
I enjoy watching Copa Libertadores here, or at least when fans were allowed, because in the latter stages it does have spectacle. Some of the derby matches in Argentina are the same. The Boca vs. River final in Madrid showed that. Hardly one for the purists but undeniably entertaining. For clarification, I used to love heading out on the weekend and watching pub football/sunday league games. It's one of the things I miss the most. I can handle seeing poor play, it's just dissapointing when you see it on a professional level.