How durable are the IPC connectors
( IPC Insulated Piercing Connector )

We have been using them for the last 2 or 3 years, they appear to be OK although the surface area is not that big where the pins pierce the cable insulation.
I find that the beaking torque required to snap of the end bolt doesn't also feel always equal to me.

Ok, they are a lot easier to install than a linetap. Some of our U.K. linemen say that they replace these back in the UK with normal linetap style fittings.

Ray,
I've had this thought myself before.
With the Aluminium ones for jointing wires mid-span, I don't trust them.
I'd sooner use a double ended crimp sleeve, with the proper hydraulic crimper.
Having said that, we have thousands of them IPC things at work and most of us guys refuse to use them.
After all we didn't buy $$$$ crimp tools for the sheer fun of it.
If you could ASSURE me that the point contact resistance was the same for an IPC connector over time, I wouldn't have a problem with using them, but in all the failures I've seen with them, it's been because the connection has not been tight enough and has burned itself to bits.
Any shear-bolt system needs to be well tested before going on the market, IMO this hasn't happened.

In BC, many of the guys setting up illegal grow-ops love these connectors as they make it very easy and safe to steal power from a live conductor

I will add a photo soon, i have been very busy with work lately and have not always enough time to actively participate in the forums.
Regards
Ray

Pictures courtesy of RODALCO: