Do you have a favorite length for general repairs? Is there really any brand difference?

Teacher

An important difference I've heard is that the white ones aren't UV resistant while the black ones are.

I dunno about the red, green, and yellow ones I got in that variety pack long ago.

I use whatever's long enough. If it's not long enough I put another one (or two or three) in series.

Longer is better, because you can always cut excess. You can't add any to a short one.

I daisy chain the short ones together, male to female ends, to make long ones out of short ones. Clunky, but effective, especially because I fell for one of those package deals which gives you a thousand zip ties, broken down into 100 eight inch and 900 three inch. I saw some 48 inch zip ties at wally world recently,

Ok, speaking as someone who uses cable ties on a professional basis:
1) Don't buy the cheap ones. They just snap.
2) The Most useful sizes are 300mm (12") & 100mm (4").
3) Don't buy them from a D.I.Y. store. They see you coming. Buy them from a trade outlet.
4) Buy them in packs of 100. You will be surprised just how fast you go through them.
5) Your absolute minimum is 2 packs of the big ones and 3 of the small.
6) Cable ties are like 550 cord and bank line - the more the better and however much you have, you still don't have enough.

thanks all - just the sort of info I needed

Tro

Get the reusable ones. It cuts down on the wastage during "oops" moments and allows you to scavenge them when no longer needed. Overall, I've found that 8"-10" is the best "general use" lengths.

I use strong, thin rope instead of zip ties. Zip ties would be quicker in some situations, but rope helps curb my knot addiction. Plus, it's one less piece of gear I need.

This site won't allow me to link the type of rope I use. So, send me a message if you want to know.

Using a small blade or a small screwdriver you can open any zip tie for reuse. I've used them quite frequently as a cable guy (past life) and use them almost as frequently in my current job of repairing/refurbishing carpet cleaners. Not saying I make frequent mistakes or anything (whistle innocently) but I learned how to open them a while back. Check YouTube, I'm sure it's on there.

I do not think there is as much difference between brands as people want to claim. The cheap ones seem to work about as well as the more expensive ones with the possible exception of the ones that have the metal clip.

the width and thickness does matter, and that varies a lot. Thicker and wider is generally better. nylon is general the best all around material.

I would not worry all that much about UV. It takes a very long time for UV to have much effect on them. I have a bunch I used to put some fencing up almost 8 years ago and they are still fine.

Extreme cold can cause issues with them though, but normally they won't just break due to cold. The cold can cause them to become more brittle and more likely to break when moved around.