Akrapovic questions

I broke down and ordered the Akra, my TAB slips-ons are just not doing it for me. I do have couple of questions though:

1. Since it uses springs instead of clamps, I'm assuming leaks are a stronger possibility. Has anyone noticed that, and how did you fix it? Have you had to replace the springs yet?
2. And based on #1, how bad is decel popping?

Thanks!