Yep. Yes I do. That's my experience.
15 gpp is gonna be a tough arrow to throw. A 600+ gr arrow at 120 fps isn't a good option. Trajectory will be steep and my experience is that penetration will remain wanting. As trad archers we tend to prefer momentum calculations over Kinetic energy. Which is fine and I agree with. But you still need velocity to make momentum. Many polls have shown that most hunters are shooting 9-12 gpp.
I gave the heavy arrow, high foc, 43 lb with 27" draw longbow a chance because the internet said it would work. Did not work for me. I didn't even get two holes in a doe at 5 yds. And I know I didn't hit anything hard. That was with a tuffhead and surewood shaft Douglas fir at 650 gr. The next year I switched to a micro diameter arrow at 510 grains but never did hunt with that combo. On foam it penetrated much better and trajectory was acceptable but not great. The 650 gr arrow had an unacceptable trajectory after 17-18 yds. It just fell off of the map. I tried a shot at a 3d shoot on an elk at 40 yds. I was aiming in the trees and still never hit the thing. Thats not a hard shot to hit an elk with an arrow in the 9-11 gpi range. I've got a nilgai hunt coming up (small elk size), and I'm actually planning on being able to shoot my 10-11 gpp arrows at 165 fps to 40 yards (under ideal circumstances... But I'm shooting really well at the moment. Also my chrono is kind of suspect, my arrow may be faster then that)
That was my experience.
Feel free to share yours.
Now a big man with a 30"-32" draw may be a different story. I ain't that.