Hi!
Ummmm.. "little to nothing to benefit someone doing SL work?"
Excuse me, Malachi, but I assume if you say this that you haven't discovered Smart Objects?
I think that being able to match things perfectly over the seams, and to set it up once and use it again and again and again is definitely of benefit to someone doing SL work.
Wilhelm, with Photoshop CS2 and above, you can use something called "Smart Objects." Each one is simply an instance of the first one.
So, for instance, say that you want to make a waistband that goes around the skirt, and say that waistband has a pattern on it.
In a real skirt, the pattern would match on the sides, and meet up with a pattern that wasn't quite the same in front, right? But in SL, it would be a very difficult task to make the pattern match, so we just kind of settle for having it mismatched on the sides, where the seams are.
Except, with Smart Objects, we can (very easily) match it once, and then just use that for any and all patterns forever after!
Just put a strip of Test Pattern on the waistband, and Group it into a Smart Object. Use the Warp button in the Transform dialog to match it to the sides of the skirt on the back piece, duplicate the Smart Object, set the Warp to None, then to Custom, and use it again to match the right side. Like this.
(I used a finer Test Pattern in RL; but decided it was easier to see it this size for this discussion.)
Duplicate and repeat for the left side, and you have a waistband that matches perfectly over both side seams.
Replace the Contents of the Smart Object with the fabric you intend to use, and presto! You have a perfectly matching waistband with your actual fabric.
Here you see the Smart Object itself, opened up (it's the .psb object.) Anything you put in that document will appear, perfectly matched, across the seams of your waistband.
Finish up your skirt, and you're good to go.
Want to make another skirt using the same pattern, but with a different fabric? Just Replace the Contents again, and the new fabric is there, instantly, perfectly matched with no more work at all.
In fact, in this skirt, most of the fabric pieces are Smart Objects, so I can replace the contents of two things (waistband, and skirt piece,) and the entire document updates; all the fabric pieces are changed in a flash, and all I need to do is match the buttons, piping, adjust the shadows and so on.
How does this look inside SL?
Perfect, within the abilities of SL to render stuff.

Now, you might not think that's much of a benefit, and I suppose if you never did textures for skin or clothing it might not be. But, for those of us who do, and who learn to use this, it's a huge timesaver/quality booster!
Just my 2¢.
Hope this helps!