Millsap makes more sense than Griffin, he's healthier, more of a team player, less personal baggage, and by the time he's slowing down Chriss should be able to take over. He's rumored as someone the Suns want to bring in, I'm not 100% sold on it but if we do sign him, I'm ok with it.
If we're going to spend the money, I'd rather it be on Millsap than Griffin. Griffin isn't an option, which is great IMO, but Millsap isn't a bad move to try and get this team to start improving now. He could help us make the playoffs this year, he might not, but he'd help us improve and the young guys need to start winning. No magic switch is going to go off where they'll just turn it on. Look at Minnesota, they've been together for 3 years and they haven't improved much at all. They went out and got Butler to hopefully help them over the hump and get them into the playoffs. They have a better coach and better youth than Phoenix. They weren't going anywhere though with what they had so they had to gamble on Butler helping them take the next step.
Teams rarely take the next step on their own, it usually takes someone being added to get them their. PG and PF are two needs, PF much more than PG right now since Bledsoe is at a top 10 PG in the league, closer to 10. Chriss isn't a starting caliber NBA PF right now and we don't have a legit starter at PF on our roster. Bringing in Millsap for him to learn from should only help him. Millsap has made the last 4 All Star teams, and should help him develop better than getting outmatched in games and playing against the likes of Bender, Dudley, Williams, and Chandler in practice.
