Considering getting some Tune King/Kong hubs, and just wondered what they're like in use ie durability, issues etc?
yes and none!
they have an alloy body so get cut up a bit as expected but otherwise have been great.
Have a set of road wheels with Tune hubs (bought used). Freehub is very soft, and expensive to replace. Otherwise no issues. I wouldn't pay the new asking price for them. Tune have had some quality issues in recent years, not sure if that's sorted now.
I'll be using an XX1 cassette, so no issues of the cassette cutting in to the freehub splines.
I had a King and Kong Superscharf a few years back. The rear fell apart (literally, bits of freehub body everywhere) and wasn't user serviceable, which annoyed me - had to unbuild the wheel and return it for the freehub to be replaced, at great expense. Not an issue on a standard Kong though, and I think even the Kong SS has been 'fixed' since.
The freehub bodies are expensive, I pondered another pair, but was put off by the additional cost to 'upgrade' to an XX1 body.
Tune have had some quality issues in recent years, not sure if that's sorted now.
This is the reason I'd never buy Tune- too many poor durability stories and expensive repairs. I haven't ever used them myself but don't think it's worth the risk to find out if the stories are true given there are so many hubs that are either lighter or cheaper for the same weight (Syntace HiTorque MX, American Classic, Carbon Ti X-Hub, DT Swiss 240, etc) with a much better reputation, so Tune would be way down the list. I guess they are shiny though....
Pretty colours too!
FWIW I've ordered some AM Classic hubs from the US - $350 shipped for the pair, XX1 freehub body, X12x142 and 15mm thru axle out of the box. Probably get stung for tax/import etc, but still not too bad and far cheaper than Tune.
I've also had a tune rear hub fail. Cracked spoke holes and the dreaded free hub body.
I pretty much only use American Classic or dt 240s on everything now.