This is a response I made to the post at CU. I just wanted to share...

Due to the opportunity that SGC has to utilize the 1/2 point scale, the SGC 98 is generally a stronger card that the PSA 10. Likewise the 96 is awfully hard to come by sometimes as the 92 option is available to SGC when a card has a flaw the needs forgiving. That does not mean that PSA 9's & 10's are all soft or lesser than SGC's. Both companies exercise a fair amount of random designation to this very subjective plateau. I own hundreds of fantastic PSA 10's. Generally, I keep 1/4 of the PSA 10's I buy. The other 3/4 are often glorified 8's or marginal 9's. I own a half dozen SGC 98's and my retention is 100% on that small sample. It's pretty darn hard to find anything obvious on an SGC 98.
PSA 10's often leave some trait to be forgiven. These include: Poor focus and registration, weak ink-strike, chipped edges, tilts, poor centering, 90/10 or worse reverses, glossless surfaces, one or more soft corners, to name a few. SGC may well holder cards with these attributes as well, but they will do so far less frequently. The consistency SGC has is due to fewer graders, longer turnarounds, better training, and private ownership. They simply spend more time grading and less time answering to share-holders. One could argue that if SGC were as busy as PSA, they would be just as inconsistent. I disagree with that baseless and empty argument.

In recent months (since early 2004), the PSA 10 has been given more frequently to stimulate submissions on many borderline or downright undeserving cards. This decision by PSA, I believe, was conscious and the residue of that short-sighted decision has eroded the value of the post-war 10 in many cases. With exception to low-pop registry singles and notoriously difficult cards on everyone's wish-list, PSA's added value has declined dramatically. SGC is seeing their cards steadily increase in value. Many HOF'ers and regional star cards are outselling their PSA counterparts with regularity. Again, not ALWAYS, but often enough to take notice. SGC will seemingly never outdistance PSA when it comes to commons, however. The blind and misguided zeal with which regitry participants chase those cards is a psychiatrists wet dream.
I liken it to mice in a maze seeking cheese. So do we seek peer validation and bragging rights to satiate our fragile "want-it-all at any cost" ego and mentality only to find a card in a plastic case with a number on it that is special only because some guy you've never met with no more credentials than you said it was NM/MT 8! I feel I can state this as I, too, have fallen prey.

I digress...On topic,

SGC is gaining every year in acceptance with novice collectors. The astute collector has recognized SGC as a quality product for some time. Only a truly unenlightened and closed-minded collector would say anything negative about SGC at this juncture. They may not be your choice, but they are the most consistent and offer tremendous customer service and cater to the collector rather than the dealer. Dealers purchase SGC graded cards all the time, by the way.

Cross-overs are a poor judge. This is due to a number of reasons. First, the submitter. I have never had an SGC card fail to cross. We're talking well over a hundred cards. I have had two SGC 92's make PSA 10. I have had eleven SGC 96's make the "Gem Jump" as well.
On one submission, I sent Joe Orlando 47 SGC 96's. Some of the finest 1977 Topps cards I had ever seen. I asked him to cross them in the holders. The results....
44 of the 47 crossed to PSA 9 (no 10's...a joke) and three failed.
I cracked the three "failed cards", including a Pete Rose, sent them on my next invoice and got two 10's (Yes, the Rose) and the other a PSA 9.
Obviously, the Rose was too expensive a card for $5 to put in the "9" holder on a cross-over. However, at the $10 rate it went from an apparent PSA 8 to a deserving PSA 10.
Bobby stated his poor results. I suggest you examine your standards or re-submit those cards. Typically the error is on the PSA side. Not always--but typically.
The Second reason is that card companies are inherently biased. Never attempt a cross-over in the holder. I learned that one first-hand.
Further, high-grade MINT cards are subject to the pace of the grader as well as his moods and other factors. Heck, it would be hard for us to grade our OWN cards the same from one week to the next. When splitting hairs between NM/MT+ and MINT and GEM, these variables are magnified.
There are other valid reasons why cross-overs are a poor test, but these are the obvious ones.

<< true, SGC seems to be a little more lax on centering issues when considering whether or not some otherwise gem mint cards (especially vintage) >>

Absolutely NOT true. That reputation was founded in the early days of SGC. Their head grader just didn't think centering was that important if the card had strong eye-appeal. This led to many fresh and sharp cards with 66/34 and 72/28 centering getting into MINT holders. Hence the reputation. That is many years ago now and, today, SGC's centering standards are every bit that of PSA's and then some. You will find exceptions like the SGC football cards that "wolfbear" posted last month, but generally speaking SGC figured out the industry accepted centering standard years ago and applies it second to none.

In the end, collect whatever gives you your little hobby chubbie. No one cares. Each of us lives in our own little hobby world where facts are often out of place and reason gives way to rhetoric. SGC is likely the most collector-friendly company available and they have stayed the course and kept their collective noses clean. I trust them and admire their ability to maintain integrity amidst opportunities to get in bed with dealers the way PSA and GAI do. Those are dealer-driven companies. Both grade cards very well, but I feel compromise at the foot of the dollar. They're the "Aerosmith's" of the grading world. With that said, I still love Aerosmith so I make excuses for them; just as PSA's loyal fan-base has been doing since early 2004