I took my 270 win to Africa last year and took a kudu, gemsbuck, 2 zebra, impala, warthog and an eland. I will admit I was a bit nervous when shooting that eland, even if the shot was less than 50 yards, because I didn't believe I had enough gun. That eland only went 35 yards and none of the other animals I shot went over 50 yards. I really like my 270 and can shoot it without a flinch. In fact, I was lined up on an impala and pulled the trigger but had forgot to chamber a bullet. I remember the PH commenting that I didn't flinch on the "dry fire."
In any case, recently I have studied multiple ballistics charts recently looking for a new gun that would deliver a lot of impact wouldn't the recoil of a 300 win mag but still have the knock down power. In my opinion, you can't beat the ballistics of the 270 WSM. It has more energy at 100 and 200 yards than a 270, 30-06, and a 7mm Rem Mag. I bought one back in August. While the recoil is more than the 270 win, it is not as much as the 300 win mag. I think the delivered energy difference is not enough to make a difference between the 270 wsm and the 300 win mag. If you enjoy shooting your gun and can shoot it well, you will have success regardless of caliber. Shot placement is the most important aspect of any gun's effectiveness.