I never looked twice at the Marlins. I don't have anything against Marlin, I love their mod. 60s but I don't know about larger calibers
There's absolutely nothing wrong with the X7s. In this case, you'd be looking at an XL7 (long action) for .270 Win or .30-06.
Most cheap rifles are exactly that: They were designed to be cheap to build, and don't have the fit, finish, and quality level of higher priced rifles. (Some "cheap" rifles: Many Savage/Stevens rifles. Remington 710. Remington 770.)
The Marlin X7s should be classified as "bargains", not cheap. They were engineered, from the very beginning, to be cheap to manufacture - yet bring the fit, finish, and quality levels of rifles nearly twice the price.
My XL7 out-shoots every other rifle I own (.30-06, gift from my wife
).
As for the Ruger vs Remington question-
I prefer the Ruger stock shape, and material. I also like the three-position safety. The 700 SPS isn't a bad rifle, but I would buy the Ruger.
See which one fits you better.