This is something I've been keeping track of, since I started making a game in Fusion 2.5. I've noticed that MMF2 basically runs games much smoother, with no framerate drops. I made a badly optimized game in MMF2 and it ran buttery smooth, with no framerate dips. The game used about 120mb at runtime, had big sprites, the game was a bigish resolution, the events were messy and all over the place, but it worked flawlessly.
With the game I'm making in Fusion 2.5, I've made MUCH cleaner events, all put into different groups that activate when needed and deactivate when they're not used. The graphics are all a much better size, and the game's resolution is small, quite a bit smaller than the resolution I used in MMF2.
However, I can see noticeable spikes with framerate drops in the Fusion 2.5 game. I have a counter set to display the framerate, and it randomly dips down to 54 fps when it decides to. It seems really weird, considering the game uses only about 40mb at runtime, the frame size is pretty small, and the game is better laid out than the previous one. I've checked all the display options and they're all fine. V-Sync is switched on, the game is set to run at 60fps, the display mode is Direct 3D 9.
Has anyone else noticed Fusion 2.5 performing worse than MMF2?