not a "big" increase, only like 4-10 WHP , BUT.... the drivability will be way better plus you can do many other changes... raised rev. limiter.... removed speed gov...rear o2 sensor del. for header....disabled EGR.. and alot of other things!
I just did it (SCT Xcal2 from Focus sport)with about the same mods as you('cept 4-1,no cat,2.25flex).Let me say....It is worth the $379 bucks and I would do it again.No more hunting/bucking at part throttle openings,way better torque below 4k rpms, and it pulls nice right into the new rev limit.It just makes what you have work better.Aint life great!Oh yea,you also get this nifty SCT chrome badge/emblem for your car.That's good for at LEAST 25whp!!(on the eye dyno,,,)