Well, I seem to have come into this late, but the 7x57 is a brilliant cartridge.
The 30-06 can be had in any form or combination but the grand old 7mm Mauser created by the late, great Paul Mauser is sadly becoming harder to find and more fool those who are enabling this.
It has power enough to take almost all big game and very mild recoil.
Roudy is right the 30-06 in Mauser action thing although in a different way.
Brazil rebarrelled their 7mm Mausers to 30-06 mid way through the 20th century, probably because they could purchase cheap mil ammo from the USA, but the action is much better suited to the original 57mm case rather than the 30-06's 63mm case and it involved a certain amount of magazine lengthening and other reworking to have them feed reliably.
The 7x57 is a perfect round to reload.
Frankly I don't know what Aardvark means about overloading it as good brass will last ages and is safe to boot.
The current US factory fodder is loaded to truly anaemic SAAMI specs that were established to ensure that fools with suspect Mauser 93s or Remington rolling blocks would not shoot hot loads through them.
The M98 is well up to 50k psi and more and even the 93, 94 and 95 Mauser in 7mm are quite up to 45k psi, which is considerably higher than SAAMI spec.
The good European ammo like Norma or RWS is seriously powerful although exy.
So get yourself a nice 7x57 and load it up to around 50k psi.
It'll match and better a 7mm-08 at the top end of it's loads, loves heavier bullets, uses less powder than the '06 and generates less recoil and the choice of projectiles is very wide.
Can you tell I'm a 7mm fan?
Incidentally, if you've already bought what did you choose?