I have that same Leupold scope, and also a Meopta Meopro very similar to that one (same reticle but a little higher magnification range (4.5-14). They are both great scopes. Glass is excellent in both, as is tracking so far. The CDS system is very easy to use and that's what I would go for. He should decide what ammo he is going to shoot, and get the CDS reticle for that load, along with the expected elevation/temperature. BDC reticles can be tricky on second focal plane scopes. The CDS would be more foolproof in my opinion, but he should shoot it to verify that it hits where indicated at long range.
