I expect Jackson to do very well in Detroit. I don't think he's a superstar in the making, but he'll be a quality starter. I think Detroit got the most talented player in the trade.
I get why the Harden comparisons are made, but he's never been--and will never be--the player that Harden was and is. Comparing their stints in OKC, Harden was better and younger (he was 22 years old in his last game in OKC, whereas Jackson turns 25 this April). Harden was far more effective on and off the ball. While he wasn't as athletic as Jackson, his shooting not only better spaced the floor for his teammates, but it commanded enough respect from defenders that it opened up driving lanes. Jackson also couldn't get to the foul line like Harden. Even as a 20-year-old rookie playing 22.9 minutes per game and using 20.4% of possessions, Harden attempted 3.2 FTs, whereas Jackson can't even crack 2.3 FTA as a 24-year-old playing 28 MPG and using 22.6% of possessions.
I've been a fan of SVG the coach, but it remains to be seen how good SVG the GM is. Coaching a team and constructing a team are very different tasks. Very few can do both effectively. The Meeks and Butler contracts were bad but far from crippling. He probably should have cut bait with Smith over the summer rather than letting his value plummet even further.