Re: Savage Axis??
Other than Rifle Basix triggers (since our two Axis (Axes?) had 8-pound triggers) I don't know about upgrades, but they do shoot. We gave each of our sons, now 14, an Axis in .270, and I have shot sub-1/2 MOA 3-shot groups (these are hunting rifles, not heavy barrels) at 100 yards with at least 6 or seven different loads with one rifle and at least 3 or 4 with the other. One group was less than 1/4". They may feel cheap, and the stock is light and flimsy (but easy rifles to carry while hunting), but they easily outshoot my 700 and my Vanguard with handloads. I'm no benchrest shooter, but bugholes for $300 impresses me.
Obviously, it depends on what you plan to use the rifle for, but I think there is a place for the Axis.