Hey there. The A700L and the Evo are different beasts to some extent. The A700L is a very steery car, a bit more aggressive, and very good on lower power classes like 17.5 . Its also lighter. The Evo has a bit less steering, but can handle bigger power classes better. It seems to be more behaved and tame going through corners at high speeds.
If I was running Mod or 13.5 and above, an Evo is very nice. If I was running Stock, The A700L is very good. If you are on the fence, the A700L would be the one I would go with because you can always change it to an Evo later if you want.