Personally I find Ambrose to be overrated as a worker as well, certainly not to Reigns at all. As a note, I was watching with my friends and a true casual fan; the casual marked out like mad for HHH and was underwhelmed by Ambrose.
I disagree with the idea that the fans will revolt against any "future top star" that the company designates, because if that was the case, why didn't the fans revolt against Reigns at Survivor Series 2013 when his push really started and he cleaned house in his match? Or during the bulk of Rumble 2014, when he went on a tear eliminating everyone? Or during the Shield/Evolution matches, when he was the big focal point of both events? The backlash only started during his singles run when he was both exposed as a worker and hindered by bad booking - and to his credit Reigns has improved leaps and bounds from then.
Which NXT match didn't you like (or both, of course): Zayn/Stardust or Revival/Enzo & Cass?