Well there are some things to consider with these two clubs. What kinda handicap do you have? Are you pretty consistent with hitting the center of the face. The main difference between the AP1 and AP2 is in the swing weights which is D1 for the AP1 and D2 for the AP2 and the lofts in the clubs are different. The AP2 stick to a more traditional lofting. Here are the club lofts
AP1
4(22)
5(25)
6(28)
7(31)
8(35)
9(39)
PW(43)
AW(47)
AP2
3(21)
4(24)
5(27)
6(30)
7(34)
8(38)
9(42)
PW(46)
There is nothing wrong with stepping up to a better club, but somethings to consider is make sure you get fit for the club that fits your game. I would recommend possibly doing a combo set as going like 5-pw in the AP2 and get a 3 and 4 hybrid to replace the irons if not the 3 iron for sure. I'm 1.9 handicap and still play a 4-pw(714mb) and a 816 3 hybrid.

Best way to find out which would be best for you is to set up a fitting session with a certified Titleist fitter and see which provides you the best performance. By going through the fitting session you can try both AP1s & AP2s with different shafts to see which head/shaft combo gives you the best all-around performance.

Listen to Barry, best way to address your question....

What's your handicap?

I went from the 716 AP1 to the AP2. The only difference I found was a slight loss of distance. However, the more I play them, the more I'm getting some of that distance back. Love the soft feel and the instant feed back. Make sure you get fit!!! Enjoy the journey.