Never looked through a Cronus, but I have the big Razor spotter and have been really happy with it. Also you can't really go wrong with the Vortex warranty.
That said, I'll just throw this out there: Bino's might be worth consideration. (There's some pretty good deals on SIG BDX 3000's right now if you want an integrated LRF solution and own a BT Kestrel.)