I did a couple of Comcast PRI circuits in Minnesota a few years ago, both were wham-bam-thank you ma'am and work great with no issues... Same with Midcontinent Communications and Charter Communications, their PRI's just work every time. Basic NI-2/Bellcore and pretty much everything default on every one I installed and they just took off.
Now, recent LEC PRI's are another story... but for another thread.