As a person who makes his living building custom rifles I might as well throw in my 2 cents worth! Winchester cut their own throat. The newer mod. 70s were all over the spectrum as far as quality and accuracy. I have seen Super grades in .416 Remington which would not feed and if fired the floor plate would fly open. Why should a person have to either send in their new rifle to Winchester or take it to a smith in order for it to work as it should have when it left the factory? Now do not get me wrong but I have seen some good examples also but in my line of work not too many. If they work right and shoot well people do not bring them in.
As to quality and features look at the CZ 550 Magnum it has many things going for it.
Now to stick up for the mod 70 a bit you must keep in mind several things. First if you want a forged and machined reciever like the 98 Mauser, the price goes up, many of the other features mentioned mean the same thing. The only way to do all these nice things is to either cut profit, (Doubt You will ever see that) or find ways to cut corners.
If you want all these things with the quality you are asking for then you are asking for custom quality from a guy who punches a time card and does piece work., unless you are willing to pay a substancal increase in price. There are people who will pay the price for a "Perfect" rifle they are the ones who keeps me in business.
Now as to improvements the Mod.70 has a lot going for it!
However I would give it a bit more of a recoil lug for starters this really would not increase price. Second look into a tang safety at least on some rifles. Third LOOSE THE COUNTER BORE AND EXTRACTOR CUT!!!! You can have reliable CR feed with out these cuts which would cut cost if eliminatedand also allow Winchester to offer the same chamberings in both right and left hand at no additional price. This is some thing no other company offers! Last, Winchester should go to places like this and find out what their customers want and liston, some thing not done by other companies from what I can see. By the way over a third of my customers are left handed and if that holds true for all the shooters out there it is a substancal market!