Nylon vs dynex sewn slings/runners. Which do you prefer and for what uses?

For research purposes  

A few nylon for racking and/or cleaning and dyneema for all else. Nylon are cheaper and more comfy over the shoulder with gear hanging off them. 

Nylon.  More versatile.

Perlon dynamic runners and Spectra Draws for the crag. Nylon Alpine Draws for, well, Alpine climbs.

I have exactly zero nylon single length runners and a whole pile of dyneema. Have a couple of double length runners in nylon, dyneema, and the "supertape" blend made by Sterling and Trango (and others?). Dyneema is lighter, packs smaller, and doesn't freeze up. If you need to cut and tie dyneema, it's a bit of a pain, but I'm not in the habit of doing that too often, so it's a non-issue for me.

Nylon for anchor slings, Dyneema (dynex) for extending pro.

Nylon stays strong longer and doesn't slip as much when used in a girth or clove hitch. Dyneema is lighter and thinner.

All my alpine draws are 8mm dyneema slings from Mammut and DMM. My over the shoulder slings that I use are the Sterling nylon 24 inch, as well as some 30cm nylon slings for shorter extensions.  

It was just trial and error that I found this combo that worked for me. 

dyneema for alpine draws, have a few nylon kicking around still use em for random stuff mostly

for sport dogbones, have a few dyneema with light carabiners for weight saving trips, but mostly use nylon for projecting and grabbing draws and stiffer so easier to clip. (all my sport draws have 18cm slings and get mixed use for sport and trad)

I do not own a sewn nylon sling. 8mm Dyneema for almost everything, plus a few of the BlueWater Titan double lengths for anchors. 

I use skinny slings (Dyneema/Spectra) for alpine draws, but have a few nylon 2 and 4 footers for tethering and rap extension, especially for new partners who may be less careful to avoid slack (at the anchor) or rope rubbing (on rappel).

I use double length nylon sling to extend rappel or make a PAS for cleaning. Mostly because its easier to untie an overhand knot or a clove hitch with it, and if you fell on it while using as a PAS its much safer than dyneema (see this scary DMM video showing 2 foot direct falls on slings).

https://www.youtube.com/watch?v=SY12o2FxjpU

For alpine draws, I use mostly dyneema to save weight.