I like my 270 but I have killed deer with both. Bottom line is the fact that the deer won't care. I think it is personal preference. What are you more comfortable with? Are you recoil sensitive? Is there a way you can shoot one of each before you buy?

I debated the same thing before I bought my go-to deer rifle but I went with the 270 in case I ever had the opportunity to hunt elk. I would feel more comfortable with the larger caliber. That is most likely just a confidence thing. I haven't regretted the 270 purchase for one minute. 270 loads are usually easier to find if you need to buy unexpectedly too.