MEK is very similar to acetone in its effects. They both can absorb into plastic chip carriers, which could cause problems, as well as removing any markings, whether they are inked or laser marked. Indeed, acetone (or MEK) is a good method to detect fake black-topped chips because the black coating will get rubbed off. Removing silkscreen print is another possible effect.
The question in choosing a solvent is what type of soil do you need to remove, and how powerful a cleaning is required? Using a solvent that is "FAR better" is not necessarily a good thing because it will remove more material than desired.
The other part of cleaning is technique. Just rubbing some solvent around until it evaporates won't remove any soil! Where did you expect it to go? Cleaning must transfer the soil to a waste receptacle of some kind, either by flushing with large amounts of solvent so it runs off into the bin, or by agitating with a cellulose towel so the soil moves into the towel. This is why fast-evaporating solvents are usually a disadvantage for cleaning circuit boards.