DPG4450GUY  Have you even looked at OmniWeb's EXCLUSIVE features, not available on any other browser?

Many people find those features enough to qualify for purchasing OmniWeb.  
(Version 5.5.2)

DPG4450GUY  First and foremost, the difference is Mozilla has been dropped from further development by the Mozilla Org. This occurred many months ago, and the only Moz Suite updates are those for critical security issues. Don't expect these to continue much longer.

SeaMonkey is a continuation, of sorts, of Mozilla suite with additional features from the open-source community that were not taken up by Moz Org.  
(Version 1.0b)

DPG4450GUY  Uh,no - your own lack of pre-update maintenance did that.

Always repair permissions and run either the Disk Utility Repair of a third-party product like DiskWarrior against your drive prior to installing applications - ESPECIALLY ones that write to the kernal.  
(Version 4.5.7)

DPG4450GUY  Installed with no issues - runs fine.  
(Version 10.3.7)

DPG4450GUY  Tell me, exactly, how this is "essential"?  
(Version 2.6)