I like the 66 blocks rather than the 110 blocks. For me, those were a PITA
110's can be a pain to troubleshoot as a double punch or hanging shiner from a previous lackey is hard to find.... BUT, there is no other way to make a CAT 5e or CAT 6 connection leaving us with little choice.
Much of the work I was involved with was older buildings (sheriff, courthouse, small towns) and the darn things were NEVER properly documented. A typical phone switch we did was not only 911, but replaced the existing building BUSINESS line switch, so you had to figure a way to ID all the lines
We had a number to call that would auto ID the line.... Damn, it's been a while but all I do now is mostly T-1 PRI lines and diagnose with a T berd :)
The telco companies were strangely uncooperative, because THEY had just lost the bid on teh 911 system. And, SOME of those lines were special. Dry copper for remote radio base stations, remote siren activation (fire, emergency) and yeah, the old fashioned alarm modules
LECS and those associated were pissed. This was thiere domain for generations... I used to find multimode fiber connects pulled right in the LEC on our rack. That stuff just doesn"t fall out. Joe Nachio fkd 'm, I didn't...
One town I worked, I think it was Ritzville, asked the sheriff who to contact because we need to move/ reconfigure the alarms. He said, "hell I don't even know if they work." We could not figure out how to contact, so we finally just UNHOOKED one of 'em. NOTHING happened!!! The bank didn't call, the alarm company didn't call, NOTHING. So we tagged the lines, unhooked the modules and tossed it in the basement. Last time I was there, that's were they were
(I can't even find a photo of one, remember? They had a red and green light, and a meter to show the current monitor limits)