Well a lot depends on the condition of your present system. The stock system, correctly setup, works pretty good. If your box, rag, or linkage have some play in them you will have issues. The problem with common boxes is they don't address the issues, some are not very good at all.
Aftermarket systems like the rack or jeep setups are good. They are faster ratios which may not be what everyone likes. They are also more expensive and require some modification.
All depends on what you want, some will tell you one or the other is better but few of them had a correctly built box to start with as comparison.