There is nothing good nor bad about the Win 70 action. For a real shooter, you will likely need to check and correct the factory tolerances, just like a Rem 700. From there, it will work as well as any 700.
There is little issue using the long action in a 308 but as said earlier, if you don't need to, use something else. Choices in 6 to 7mm are so much better.
If you are really on a budget, sell the Win as is. Take that money and pick up a Savage HB in 243, 223 or even 308. You will have a much better rig right off and it will likely shoot as well as you need for a very long time. Stocks are readily available now as are other accessories.
If you want to build a competition rifle, barrels can even be swapped at home.
Jerry