I wonder what sort of fluctuations we can expect seeing as the original was built around necessity rather than stability. The environmental set pieces for example intentionally took a performance hit to provide more detailed surroundings. It worked well since those scenes generally had you just walking from point A to B while admiring the view (so never felt sluggish), but they increases the gap between the original and the new target. Those scenes tended to hover around 24fps (20 - 28), so the jump for it to be a solid 1080p/60fps would be somewhere around 650%+. That's without even considering the upgraded assets and AA o_o
If they manage to lock those scenes at 60fps and i'll be pretty impressed. That would be some serious dedicated for a port 
