The newer formulations, applied and used properly, seem to be better.
Plain cyanoacrylates (e.g. the lower-viscosity ones) seem to be rather brittle. They don't deal well with materials that flex at all, and are best reserved for entirely-rigid materials. The low-viscosity types have very little gap-filling ability - work OK on clean breaks but not well if the joint is rough and has any air-space.
There are newer varieties - composites of cyanoacrylate and other materials, sometimes including what seems to be something like nanoparticles of rubber of some sort. These are often marketed as "toughened" cyanoacrylate. I've had better luck with these, when used as a more general-purpose adhesive. I presume that the added materials prevent small fractures from propagating through the solidified adhesive. The occasional ceramic cup or dish I've repaired with the toughened cyanoacrylate have held up OK.
Low-viscosity cyanoacrylate also makes a nice quick (and hard) finish for small lathe-turned wood object such as pens. You can use it as a structural fill, too... put a few drops into a hole, sprinkle in some baking soda (sodium bicarbonate), stand back while it fumes, and wait a minute. The result is a rock-hard white solid. To fill large holes, do this in repeated small layers for best results (warning, it exotherms a lot for the first few seconds - hot enough to burn you).
Another good one that a friend turned me onto, a year or two ago, is West Marine's G/flex 655-K. It's a thickened epoxy, sold for the purpose of repairing plastic boat hulls. It'll bond a lot of the more difficult plastics (flashing a torch flame over them for an instant is recommended - this oxidizes the low-surface-energy plastic and creates bonding sites for the epoxy to react with) and it works a charm on metal and wood as well.
My friend learned about it when he asked a supplier for a glue to use when installing stone counter-tops. He tried it out, epoxying a length of pipe and a flange to a piece of polished granite... just scuffed up the surface a bit with some carbide paper and glued the flange down. After it cured, he banged sideways on the pipe with a sledgehammer. The epoxy didn't fail, the steel didn't fail... when he managed to bang it free, the granite failed, and a bunch of crystals tore out of the slab and remained firmly cemented to the flange.
The kit isn't dirt-cheap but isn't ridiculously priced, and you get a lot of epoxy (8.4 oz). It's become my general-purpose go-to epoxy.
You'll also learn why it makes good sense to buy a small bottle of cyanoacrylate de-bonding liquid, and keep it in your shop next to the cyanoacrylate adhesive. Cheap insurance against torn skin, and having to admit an embarrassing oops to one's significant other :-)