4 ton or 5 ton central air conditioner?

by Kenneth
(Dallas)

I have a 2100 sf home with 12 ft ceilings and open floor plan. I am located in North texas where we have high 90s to 105 for two and a half months per year.

I am replacing my 4 ton HVAC system. The 4 ton has done a decent to good job. Will a 5 ton do better or will it be too much for my size home?