Great comments over the last few days, all of you.
I continue to keep the PA23 in the bag, as it's just such an enjoyable frame, from serving to ground strokes, even not half-bad on volleys -- this coming from someone who, like many of you, has been grounded on thinner, boxier beam control frames, some with more tweener characteristics than others.
IMHO, the PA23 is quite possibly the best bridge frame for someone looking to get into this genre. The tighter mains allow for a more direct and/or flat swing path with pleasing enough results, even though it's not really the optimal stroke mechanic to get the most out of it. When I play the PA23, I'm consistently finding myself in some combination of having to and wanting to use a more western grip on the forehand, and switching from a Wawrinka-style flat OHBH to a more swipey, Gasquet-style, or, more often than not, a 2HBH, as it just seems more optimized for the PA23 (high twist weight, cumbersome for just one wrist). I'm still coming to grips with more uncontrollable launches than I'd like, usually when I don't setup properly and hit too flat without enough face angle worked into stroke, but overall, it's a whopper of a frame, a job really well done by Babolat.
As a value-add to the thread, I think TennCom did a fantastic job recently of casing through all generations of the Aero, and they came to the conclusion that the PA23 is overall the best one yet, which is very interesting, if not telling, on how good a job Babolat did:
As for customization, I'll repeat myself as I did before -- the PA23 is
highly tuned in stock form, and is very sensitive to added weight. In my opinion, it doesn't really need any weight towards 9 and 3, and only 1-3g at the most at 12, with minimal counterbalance in/around the handle. I personally only needed 1.5g at 12 for a 328SW with Black Knight 1.28, plus one over grip, to get the racquet playing just about perfect. So to everyone playing with weight, I would take it easy: increment in .5 to 1g amounts, and with such a high twist weight already, keep it close to the 12/6 centerline, as it certainly doesn't need much, if any, out at the sides.
As for strings, the best I've tried so far is still Black Knight 1.28, with tension in the low-mid 50's (lockout, so ~50 on an eCP). This gives you a medium-firm, calm, dampened, controlled, grippy string bed with high playable longevity -- a nice counter to the frame being fairly raw in feel, having a decent amount of trampoline and still being a string-eater (despite the tighter pattern). I'm still intent on trying Grapplesnake Tour M8 1.30, either full bed or as a cross to a shaped poly main in of 1.28 to 1.32 gauge, and also YTEX Penta Power 1.28, and will report back on that soon enough.