Are you mixing up the AP1 with the AP3? The AP3 looks very similar to AP2, not AP1. The blade length is a touch longer on the AP3, but looking down at address it's virtually unnoticeable. Same thin topline. Or are you speaking specifically of the way they look alongside the AP2s in the bag? If you played blades and liked them, you will like the AP2s complemented with AP3s in your longer irons, rather than AP1s, IMO. I used to play two AP1s along with my AP2-716 PW-7i, but when the AP3s came out, I immediately switched to them and have never looked back. Awesome clubs, just wish they were forged like the AP2s. The AP1s are a bit too chunky for my taste, but as game improvement irons go, they are great too. And, I will say, the 718 version is better looking than previous versions with what seems to be a slightly thinner topline than the older models.

I agree with Doug. The Ap2's and the AP 3's look similar, compared to the AP1's
I have a split set of AP2's ( 7-P) and AP3's( 4-6), and couldn't be happier with the set up. Personally, I found the AP1's looked too chunky for me at address.

You can do it but I would suggest working with a fitter to achieve this as there are issues with gapping you need to be aware of.

check out this fitting tool:

www.titleist.com/locator

My approach would be, whatever works, go for it. I have heard of all kinds of Titleist combinations with success on this site.

I will agree with Doug that the AP3 would blend better with the AP2. I think you would run into gapping issues trying to blend AP1/AP2. I have the 718 AP1s and love them, but they are about 3 degrees stronger through the set than the AP2s. The AP1 6 iron is 27* and the AP2 7 iron is 34*, so almost a 2 club gap.

I think you could go AP1/AP3 or AP3/AP2. I think a good split for you would be AP3 4-5 then AP2 6-PW.A.

Try the AP3s

I am a big fan of blended sets. I wish more people that I fit were open to the idea.

As long as you have been properly fitted, any combination is ok.

I've gone with 6&7 AP1. 8,9 & PW AP3. With 818 Hybrids to replace the 4 & 5 iron. I've had this setup for 10 months. The gapping is perfect.