The Repair Permissions function in TechTool v8 has been properly tested by MicroMat prior to release and is safe for use on OS X 10.11.x El Capitan.....this is why MicroMat didn't release v8 until after El Capitan had been released -- they were still testing it against the final version of the OS.
As I recall, MicroMat was burned pretty badly several years ago when one of the functions in an earlier version of TechTool Pro (that had worked in testing against the pre-release beta of the OS) played havoc with the final release due to some last-minute adjustments that Apple made to the final version....
Disk Warrior v4.4 (and most likely all other legacy utilities), while it might appear to run correctly under El Capitan does NOT have the capability to properly rebuild the directory now because there are MORE functions within the OS today than it (and the legacy utilities) knew about when originally designed and released....this is exactly what ALSOFT has cautioned their user-base about with the warning directing an upgrade to v5.
Yeah, I thought about that rebuild directory business with V4.4 of Disk Warrior. Fortunately, that same functionality is part of TechTool Pro.
Regarding when TechTool Pro was upgraded to V 8.0.3 (note the .3) for El Capitan compatibility, as you said, that actually happened
AFTER the release of OS 10.11, but before the release of OS 10.11.1. I also suspect that the delay in that release was not due solely to the Repair Permissions feature. I actually never planned to upgrade from Yosemite, OS 10.10.5, to that first version of El Capitan because the first beta of OS 10.11.1 appeared in early August, just about 8 weeks before OS 10.11 was released, and thus I planned to upgrade to OS 10.11.1 anyway. However, it was still my requirement that 5 critical applications needed to be compatible with El Capitan before I upgraded: 1Password, Onyx, Office 2011, SuperDuper!, and TechTool Pro. The upgrades for the first 4 did come out prior to the release of OS 10.11, but as was mentioned, the one for TechTool Pro did not come out then. Even if the upgrade for TechTool Pro would have come out prior to the release of OS 10.11, I still would have waited until OS 10.11.1 was released, which was only 4 weeks later.
Speaking of Repair Permissions, are there any differences for that feature between Onyx and TechTool Pro? I did previously ask that same question on the TechTool Pro forum for El Capitan compatibility, and I never got a definitive answer.
