Been on MF 4X, and SROS 9X...tried front and back on both. I'd say on either ride, (unlike most coasters) front row is easily best, but back is also a lot of fun for different reasons. On MF, front is best because you can't really feel that sustained wind and speed in the back, and the ride focuses on speed more than airtime. On SROS, again the ride seems faster in the front, plus the change in forces entering the airtime is more noticeable, and the air seems more sustained (when, in reality, it's about the same as the back, just occuring at different points on the hill). The first drop on MF is absolutely amazing in the back, seems really long and has maybe -.4 g's sustained until the pullout, and on SROS you get a nice pop of air on the drop, plus the ride seems a little more wild in the back.
I think SROS is much better, though MF is one of my top rides too. Superman is much more dynamic, with incredibly strong airtime and an overall more interesting layout. Its drop isn't nearly as good on Superman, and it doesn't have that sustained speed through almost the entire layout, but its layout works perfectly because it has sustained speed in parts (most notably the overbank until the 2nd camelback, and the second helix) and is more dynamic in the rest of the ride. Superman paces faster over its hills too, which is one of its main draws IMO. The lakeside setting I actually found more breathtaking than MF's setting, probably because of the scenery on the other side of the lake, and the interation with the ground and people offride was better too.
So yeah, SROS can't touch MF for height, sustained speed, and first drop quality, but what it does do right is take that 200 feet worth of speed and create pacing unlike almost any other ride, and combine it with incredibly strong and dynamic airtime, surprisingly good and unexpected lats in spots, and a varied layout with higher quality tunnels and a much better ending.