Inversions would have ruined Magnum. Let's face it, none of the Arrow loopers are very good. The B&M's are better, but the greatest coasters are still out & backs or twisters (or some variation in between). What makes a coaster great is the hands to the sky, out in the open, butt off the seat re-rideability that only a coaster without OTSR's can deliver (aside from B&M inverteds, that is). If Magnum would have been a looper it would be in the same company as Steel Phantom, Shock Wave at SFGam, Viper at SFMM, and the list goes on. Instead of mediocre, it remains one of the great ones.
Call 122 degree turns what you want, "inversions" would ruin Millennium Force. We won't know for sure until we ride it, but I firmly believe MF will be the benchmark for coasters for a long time to come. And Cedar Point knows it.