In this *specific* case, they are very different beasts. The tech cord has a Technora (fancy, high tech fiber) core and the accessory cord has a more normal core. (Nylon).

I think you need to make sure that you examine the specific cord when comparing as I don't think you can assume a given "tech cord" will be made the same way.

As far as I understand, the weakness of this product is tying/untying knots or otherwise sharp bends. I think this is related to what Pete says -- there is no weave to the inner core, so if you break a fiber anywhere along the length, it stays broken and reduces strength. Over time, that would add up.

I think the knot issue also is part of a "shear" concern, where the knot acts as a sharp bend which increases the chance of breakage. I assume this is partially due to the lack of give in this material, but I'm certainly no expert.

How much of an issue this would be, I don't know. But I tend to keep my tech cord for emergency use where I want to have a very strong cord, and would plan to retire it fairly quickly.

Again, as Pete suggests, for your utility use, the paracord/accessory cord may be better.

Probably just inspect it and replace it before it gets too ratty, and maybe carry some spare.

I tend to also like Spectra cord which is another (but different) high tech cord. This is braided and much more flexible. It is a bit 'slippery'. The 7/64" is very small, light (I think it floats) and rated for 1200lbs. It melts (makes it easier to deal with the ends) and has some give.

While you may perfer paracord/accessory cord for everyday use, the Spectra cord is a nice backup cord because it is very light and compresses well.

YMMV.

-john