I started out with TBAC by getting a 30BA for use on my DTA SRS, and except for the fugly BA brake, loved it in that application. They announced the 30CB9 not a week after I'd gotten the stamp for the 30BA, so I ordered a 30CB9, and was happy with it - until they announced the Ultra line, so I bought an Ultra 7. I sent the 30BA back for the Ultra baffle stack upgrade, and not only is it lighter than the 30CB9, it's also noticeably quieter, especially noticeable when shooting under a covered firing line. I did some group testing with a LR BR rifle in 6 Dasher built on a BAT 3L action, and found that the Ultra 7 gives considerably tighter groups out at 600yds than either of the 9" cans, which lead to further comparisons on a few other of my custom rifles with barrel contours from sendero to hvy Palma, and chamberings from 6XC to straight 284; in every case, the Ultra 7 gave tighter groups. So I called TBAC and placed an order for a Gen 2 Ultra 7 with the 6.5 aperture. Got the bad news that it'd probably be nearly a year before they could assign a s/n to that order, so when I found one of these cans in stock at a dealer, I bought it, and am waiting on getting the stamp back. I've always wanted an Ultra 5, but with the delays associated with either individual or trust form 4s, and having celebrated my 70th B-D a month or so ago, I'm wondering if I'll live long enough to get any use out of the two cans I have in jail now....