The standard handguard (black on the S, black and orange on the R) are good but are not perfect:

• They are all plastic and can deform on impact, not completely protecting the levers
• They prevent rotating the levers down as they don’t go far enough on the handlebar. If you spend your days standing up this count.
• Depending on their position the various cables are ragging against them.

Third party hand guards have better protection, and attachment points leaving more space to the various cables.

Warning: Space is limited if the handlebar is moved to its most forward attachment points, it may cause the hand guard to touch the TFT at full lock; Same punition if the handlebar are tilted forward while in the center position. See this extract from the fitting manual for the Barkbuster, but this applies to all models (especially the KTM metal one, which is a Barkbuster in disguise!):

Here is a non-exhaustive list of robust hand guards with a two point metallic wraparound. Of course there are other options, leave a comment if they are worth mentioning here. See also this thread on advrider for more options.

BarkBuster

You need to order three parts:

• First the Hardware Kit, get the tapered two point mount reference BHG-152. It’s a big aluminium bar solidly bolted.
• Then a plastic part to screw on it. Lots of choice there as most of the barkbuster hand guards mount on this. The VPS ones are a nice fit, in plenty of color choices, including orange (reference VPS-003-OR)
• A 10mm spacer and assorted bold B-078 for the right side otherwise it may interfere with the brake lever.

Acerbis

The X-Factory is cheaper than the Barkbuster for a similar protection. This is also available in plenty of orange versions (black/orange, orange/black, white/orange and orange/white). The metallic bar is steel, very very robust. The Acerbis also require an additional 10mm spacer between the handlebar mount and the bar on the right side for a perfect fit (10mm might be too long, there is a report that filling it down a bit prevents it from hitting the TFT display at full lock, see the warning at the beginning of this article). Example of install.

HighwayDirtBikes

HDB makes an interesting model that uses the bar clamp as support location instead of the handlebar. Some pics in this article. Another install reports that those ultimate handguard bolt nicely in place but do hit the TFT. There is a detailed install report on this advrider post.

KTM

KTM also offers a handguard with a aluminium insert, that mounts on the 790, p/n 63502979000EB. Turns out this is an OEM Barkbuster frame with different plastic on it. See those two install report.