I have both rear blade and roll over box blade. I also have a hydraulic top link. The top link does not make either the ROBB nor the rear blade WORK BETTER - it makes adjustment of both easier. However - easier adjustment will usually make then work more efficiently. I can state for a fact, in my case, the hydraulic top link made my learning of my rear blade go much faster. Same for the ROBB.
I've seen guys that NEVER make an adjustment on their rear blade. I'm - more or less - the opposite. I will tweak that top link until the rear blade is doing the very best it can.
To each their own.