My first target rifle ('93) was built on a Winchester Model 70. It's no longer my main target rifle, but I have it set up as a .308 F-Class rifle. Had it out to the range this past week shooting at some angled steel plates (designing a bullet protector for a microphone sensor array).
M70s are similar to Rem 700s, in some ways they are "better" and in some ways they are "worse". The Rem 700 has by *far* the advantage in aftermarket parts, that is definitely an advantage for the 700. Generally the M70 aftermarket is adequate though (I had the choice of two or three one-piece scope rails for an M70, whereas there are probably a dozen choices for a Rem700).
The M70 has a square flat bottom and its recoil lug is part of the receiver, whereas the 700 (and Savage 110) use a separate recoil lug that is sandwiched between the barrel and the action. All sorts of religious opinions abound on which is better and which is demonous, of course, but the truth is that really good rifles can be built with each system.
Post-64 Win M70s are "push feed", with a sliding-plate extractor (arguably on of their advantages over the 700's extractor), and a spring plunger ejector. In '97 or so, WInchester re-introduced the pre-64 Mauser-style controlled round feed, but kept the push feed design on a few of their models (their target-oriented ones, IIRC). I don't know if you *must* load a controlled round feed M70 from the magazine or not (some Mauser designs will not let the extractor snap over the case head, but many are chamfered so that this is possible).
The spring plunger can be removed if you wish, so you just pick the empty out of your action when you've fired. I had intended to do that but was initially foiled by the roll-pin, and before I got around to removing it I learned how to hold my hand so that the empty case popped out into my hand as I opened the bolt.
If you want a target-grade action, you need to assume that both the M70 and the Rem700 are "crap" from the factory, until proven otherwise or fixed. Some accurizing operations are easier on the 700, since it has a tubular receiver. To be honest, this "crap" verdict really only matters if what you want is a real F-Class rifle, in which case buying a custom action might even be cheaper than fully accurizing a Remchester (don't get me wrong, a Rem 700 *can* be made *fully* as accurate as the very, very best custom actions - but it can take a lot of time and/or money to do so, whereas the good custom actions are expected to be *right* the moment you take them out of the box).