It's only been one year and they were missing one of their key players for nearly half of it; there's really not enough to look at to say that the system can't be successful. And even from the limited sample size we have, it's already shown to be much more effective than the systems they were running from 2010 to 2013. I think they ride this experiment out for at least another year.
And the issue wasn't simply that they had an older Shaq, but that he killed their running game. Hibbert might be younger than Shaq on the Suns was, but he's still a plodding, immobile center. If you look at the Suns' bigs, they're all active, athletic guys who can move up and down the court.
Curious as to what you think: who's the better player right now, Rondo or Dragic?
Sure, no disagreement there regarding Hibbert's inability to fit into a high-tempo system.
Look how badly the Pacers screwed up by adding the wrong player(s) to their system. They were a playoff contender until the trade, that on paper made them better, but in reality made them a worse team.
I would say no as well but for a different reason -- transforming the team's identity would take longer than half a season and if they lose Rondo in the offseason, it would all have been a waste of time and assets. If Rondo promised to extend his contract, I think they would do it.
I disagree with you slightly on one point. The Suns have a "good thing" but that good thing may never reach championship fruition. Though a Rondo/Hibbert implementation would be risky, its reward is likely greater than the ceiling of this current Suns team. I think Rondo/Hibbert combined at this point in their careers is more enticing than Shaq was at that point in his career.
As for cashing in. I don't really see anybody good that is 'on the block' right now. We missed out on Kevin Love. Who else is 'available' who would actually improve the team?
I agree that working in Rondo/Hibbert would be difficult and would likely require Hornacek to adapt his style. The rewards could be plentiful, however.
I think the argument is to go for proven vets like Arron Afflalo and Al Horford and in turn it will be easier to convince a game-changing talent to join Rondo and the cast. Plenty of those types of guys available at a certain price (one that we can afford, and I say that as someone who is unsure about this method of team-building).