I guess I always take the side that my partner doesn't want, which typically seems to be the deuce side. I'll play whichever, I have no preference.
Usually, I pretty much assume I'm playing the ad in mixed if the guy has a ridiculous kicker to the BH, because most girls I've played with can't handle that big hop or out wide lunge return.
I think whenever they protest, I let them see and then it's funny to see if they want to try to switch it up in a second set or not. Sometimes you just have to let people take their medicine. I also prefer to not have every ball come to me at 15-0 or 30-15 or 40-30 as a returner in mixed at least (LOL).
I think everyone likes to think they are the stronger player because they are playing the AD side. There IS no stronger side, there are just stronger players.
I just think you play simple math: Statistically, you are just MORE likely to be playing MORE balls by playing on the deuce side because everything starts out on that side. If every game had the same number of even points, then I'd say it's a wash. But, it's not. And...I come to play, so I certainly want to play more shots!
The funny thing I've noticed is that at lower rec level doubles (8.0 COMBO and below) many people still can get a LOT of forehand returns off the deuce side, either off a runaround, a slow serve, or just because for most players serving at that level it's easier to serve center or wide on deuce side. So, you can get that FH. Much harder for players that level to get the ball up the T.
At levels above that (maybe 8.5 combo and above), you start seeing that BH down the middle a LOT LOT more. I think it's just much more part of the game and that deuce returner is really under the gun because that's usually his/her BH that has to go all the way over. It's a small window to hit into with what is usually most people's weaker wing.
Most players (at least all the ones I've seen in my years of playing) are way more versatile with their FH, they can bang it, lob it, slice it, roll it, inside out it. Because of that, I think many players feel the FH is their better shot that they actually have more court space to "safely" hit into on the ad side. I know a lot of players - even at good levels - do NOT feel that way about that BH return inside out. They know they can't get that ball over there and have to lob.
At the pro level, I think they pretty much squeeze the middle with most stuff and leave the alleys completely alone - even in rallies - daring you to try to redirect off of 120 mph serves or huge groundies and volleys. If you can do that, you are Rafael Nadal or Roger Federer or Leander Paes. You are NOT the guy at the park.
Granted, many break and key points are on the AD side, and it's always the final point of a deuce game. I just think that the AD side better player discussion is overplayed.
I think the real issue (on who should play which side) is can you return serve consistently well enough to get it away from the poacher, whatever side you're on?
Knowing tendencies, knowing all of that, that's how you should make your decision in my opinion.
I like both sides and have never tried to be "phobic" about either one. People that are like that are not people I want to play with!
Mental game? That's for people without sick timing on their forehands.