[the 'stache]

For modern cards, I am inclined to agree with those that say go with Beckett. The lion's share of my collection are Bowman Chrome certified autograph cards, and when I look to buy a graded one, I always go with Beckett.

Two reasons:

1.) Resale value tends to be higher, as there is much more detail to the final grade with Beckett than there is with PSA. PSA gives you one grade for the card overall, as has SGC historically (though I see that they have started doing half grades. I'll have to look into the specifics). Beckett gives you four "sub grades" (centering, surface, corners and edges), and those 4 numbers are used in an algorithm to determine the final overall grade. They also give a separate grade for the autograph itself.

Most people consider a Beckett 9.5 and a PSA 10 the same, with a Beckett (BGS) 10 pretty much being the king of the hill in modern cards. If you find a ten, it's pretty much a flawless card, even under magnification.

2.) The slab. While PSA and SGC slabs are sonically sealed (the seams of the slab are welded shut), they can be popped without leaving any evidence of tampering (yes, it is possible. I have seen it). Beckett's slab can be popped, but if you do it, you're going to destroy the slab, and it's impossible to reuse it. If you get a card that's BGS slabbed, you can pretty much be sure that it's the original card. With PSA (and I'd assume for SGC), there is always a chance that it's been tampered with (how much of a chance, I am not sure. I would say it's low, unless the seller has a high level of sophistication with popping them). Additionally, as was mentioned earlier, the card itself is placed in a plastic sleeve which protects the card inside the hard case. PSA's card is free to move around slightly.