The day I bought my SR/S, I picked up a number of OEM accessories, without shopping or searching out user reviews. My past experience with OEM parts has been all good, albeit at a premium price. But I am willing to pay for great fit, great instructions, and good quality. None of those apply to Zero's accessories except for two.
I'll start with the only good ones. The upgraded front brake lever is fantastic. I'm shocked at how much it improved brake power and feel. From just a lever. And the comfort is way better than the horribly-shaped stock lever. Looks great too. The price is absolutely insane however, but I'd still spend the money again. The smoked lens LED signals are beautiful also, just stupidly overpriced at $160. I believe that generic aftermarket ones would fit. Either way you have to program the bike for them.
Luggage rack: Insanely overpriced garbage and the Givi adapter won't fit correctly without extra parts. Idiots. Then once you do get the right bolts and move it back where it needs to be, the plastic flops around a LOT and the box is always bouncing. So I had to build a reinforcement from an aluminum sheet. I should have bought the T-Rex, which also has bungee loops. I had to buy and add those myself.
Speaking of Givi...the Zero branded option is an absolutely insanely priced low end box, with the only benefit being a brand sticker on it. Buy something else. For the same price you can buy from the Givi high end line. Without the Zero logo. I hated the look of the other branded box, something from Shad that is horrifyingly ugly.
Swingarm spools. I'm a moron. Again, didn't shop, didn't ask prices, the dealer was offering 15% off all parts when you buy a bike. They are $40 MSRP and worth maybe $5. You can get better spools from Aliexpress for $10. I know, I did that for my KTM. The Zero spools are crappy and tiny.
12v accessory cable/adapter. I sent this back. It was offensively overpriced and HUGE. I have no idea where I'd stuff the stupid thing. I ended up just cutting off the stupid proprietary connector and put in a standard SAE connector like they have in the back of the back. $8 from Amazon.
Touring screen. Not crazy priced at least, but for me, it results in a lot of noise and buffeting on the highway. Sure, it reduces the total wind, and increases range. At the cost of pushing my helmet around and making things worse. Junk. I'm going to try cutting it and see if I can find a middle ground. As far as I can find, there are --ahem-- zero options from the aftermarket for this bike. And yes, I tried a winglet with no improvement.
The wheel chock looks like a direct clone of the Baxley, which is what I bought, but is half the price. Shocking. But because the other OEM parts were garbage, I paid extra for the Baxley, maybe without reason, don't know. I do love it and it works SO well. Absolutely recommended. If they did just clone it, then the price is awesome.
I do like the TechSpec tank grips, but those aren't really OEM or branded. They just happen to be sold at Zero dealers. At a ludicrous price. They are excellent though, and very helpful if you like to use a sport/racing body position in turns.