I've had both Yamaha guards and Barkbusters on the XTZ. Yamaha ones are strong, physically protect hands/levers well and fit nicely (as you'd expect), but the deflectors are pants for keeping off the elements. Barkbusters IMO are better overall, but mainly because of the wind protection - choice of VPS or Storm (bigger) plastics. You do have to watch the fitment of BB handguards as they can hit the screen/clocks depending on riser/bar configuration; I had to countersink the the forward facing bolts to get them to work lock to lock with the bars set how I like them.

Had TT guards on my previous bike and they are all plastic (no metal backbone), so not as strong, but offer decent wind protection.

Acerbis are another decent alternative - see here

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