Nothing wrong with the 270, but like most of the rest of us this is likely more about want than need.
The 7mags are nice in open country and (recoil wise) are easy to hit with....There will not be much if any difference in hitting power over the 270.
If you are looking for more power at reasonable recoil levels I would suggest the 300Win. Loaded with 200gr bullets it behaves very much like a 338 yet is a bit more adept at long range shooting. The 200 Accubond at 2900-2950fps is great in the wind, delivers awesome downrange energy, and is a superb game bullet.
Flat trajectory has very little to do with hitting at long range. Once you begin shooting beyond 300 yards you should know how far the target is and you must have a known trajectory correction for the range and environmental conditions......The faster 180's will not help you hit anything more readily than the 200grs.