PCGS Labels - What's The Difference, And Does It Matter?

I know, I know, "buy the coin, not the slab". But with recent discussion about counterfeit slabs and how to identify them (in part) by the labels and/or the certificate numbers, I'm a bit confused.

1\ Is there an online resource that describes the various labels and how to identify "good" ones? I'm mainly thinking of the main types -- original green and blue, not First Strike or signature series (but those would be good to consider as well). When did the number of digits in the certification number change from 7 to 8?

2\ Is there any benefit or downside to the original green holders, now that some time has passed and new security features have been added?

Just as a matter of personal taste (i.e. OCD and high/probably-improper standards), I've avoided the green labels because they look so primitive and seem easier to copy, but that probably doesn't mean anything anymore. I've also turned away a few simply because the coins are rotated in the slabs and there's no way to fix that short of sending them back for re-holdering and I question if that's worth the expense. Re-holdering would also address my green/security issues, but again, is it worth it? I'd have to go through a local shop for this service, since I'm not a member of, well, anything yet and I don't have anything raw that's worth slabbing.