RE: SKS guards, arguments of whether they break or not aside (ime they do, they fatigue at fixing points and just plain crack through vibration) there are other better alternatives.
PDW and GB guards have external stay hoops as previously mentioned, this does give better water flow and consequently no drippage at the stay points like you get with SKS, you also don’t get the crap buildup inside them at the points where the harware fixes like you do with SKS. They’re also more liekly to clear discs at the front due to the single low stay rather than the pairs on SKS/Other plastics.
The stay adjustment and fixing on the PDW is much nicer too, just a grub screw to adjust and fix, OK you don’t/shouldn’t need to be adjusting the stays very often if at all but it’s nicer and easier than the fiddly slide and bolt fixings of most guards.
The more rigid guard and thicker alu stay keeps them more rigid too so they are harder to knock out of line, and they rattle less too, most plastic guards flex and rattle to some degree, even when fitted correctly, and NEED paired stays due to that flexibility, but as a pluss they do shrug off bike rack tussles and things like that a bit better.
Not seeing any point in upgrading my SKS…
I wouldn’t ‘upgrade’ either if I had existing working SKS guards (in fact I do have some on one bike), but when buying beacuse you don’t have a set, or to replace a broken set I’d look elsewhere, PDW expecially are avaiable for about £10 – £15 more than Chromplastics and in my opinion well worth the extra, GB are superior again due to lovely rolled edges trapping even more water, but they are more of a faff to fit due to having to drill them.
SKS are still my default suggestion to people who ask about guards as they are pretty good value, and robust enough for most users, and compatibility/ease of fitment is good on most bikes, but there are better alternatives, and it’s not just mudguard snobbery 🙂