I have the full Akra as well and have had a similar experience.
It sounds great. And while it is loud, when I see other people riding it it honestly doesn't seem as loud as bikes I've heard with Austin Racing pipes, which are wicked loud. Nevertheless, the full Akra causes me a lot of problems whereas the full Termi system on my Monster 1200S was perfect. I don't know if it's the specific frequency or the positioning of the pipes or what, but I've learned the hard way to wear earplugs on every ride. I noticed it right away, as after I rode it home I had a persistent ringing in my right ear for about half a day. I started wearing earplugs but forgot to put them in on a ride about a week ago, and again that resulted in some pretty annoying issues with my right ear. I wear a Shoei X-14, but just as you said that almost seems to make it worse.
I really enjoy the V4SF, but I have to be honest and admit there are times I wish I still had my Monster or had gotten a Pikes Peak Multi. The Monster always sounded massive, it had a boatload of low-end torque, and it never hurt my ears.
For me, part of the problem is I've heard the V4SF with lesser exhausts and, unlike a twin, I just don't think it sounds that great unless it has a full system on it. And with a full system on it, it draws a LOT of attention and can be harmful to your hearing.