I had my AP2 712's ordered half an inch shorter...turned out they don't add weight and when I had my irons checked ..the weight was way low....like C-10.....I hate my AP2's....I wish I had bought AP1's now..Cheers

You can always change your grip to Winn Excel RF to restore the swingweight.  They are 9 grams lighter than the standard Lamkin Crossline or Golf Pride Tour Velvet.  That is almost 2 swingweight points there.

So I simply need to specify that I want D2 swingweight when I order my clubs and Titleist will make proper adjustments?

They should.  I believe on AP1 and AP1 the weight insert is on the rear.   Other things to change swingweight (without changing the grip) are to put a hosel weight of 2 grams for every swingweight point (Mike, Cameron and Cathi - pls jump in).   For those of us blessed with large hands, a midsize Lamkin or Golf Pride grip will decrease the swingweight by 2 points vs standard - kills the feel a bit. 

Also, most golfers barely notice a change of 3 swingweight points.   

If you have a lighter grip you may get a little more feedback from the clubhead.  I played a set of Eye 2 Blue Dot and they were -1/4" from standard length (the 8 iron in my set was 36") and used Winn Excel RF to maintain a D0 swingweight.  My AP1s are at D1 with Lamkin grips and -1/4" from stock.  The latter have a softer feel and I knew when I mishit the former because it stung a little bit.  Winn Lite V17 or Dri Tac feel a bit harsh on irons (ok for woods and hybrids).