Does anyone have an opinion on air filters for the CForce 1000?
Recommendations on the OEM vs an aftermarket filter.
I've heard that some aftermarket filters might not fit tightly.

[2015 Z Force 800 53/Trail EPS]

Does anyone have an opinion on air filters for the CForce 1000?
Recommendations on the OEM vs an aftermarket filter.
I've heard that some aftermarket filters might not fit tightly.

Check the Info Center. There are a number of UniFilter options listed for the 1000 engines.

I came from the Rally Car and Road Racing world with high revving high boost 4 cylinder turbo cars, like the Mitsubishi Evolution X, and I have a strong bias against oiled air filters. In my experience there is no air filter of the same quality as an AEM, so when I bought my 2023 CForce 1000 Overland it only had 11km on it when I removed the factory filter and put on a dry AEM filter, and slipped a SickSpeed water repellant cover on it right away. Part number is AEM 21-2011DK. Another nice thing about an AEM is you never need to replace it, its still good in 15 years just needs to be blown clean by an air gun occasionally.
I also only run AMSOil 0w-40 in the machine, and use AMSOil Severe Gear 80w-90 in the diffs and transmission.
If these products can keep an abused rally car ticking, its more than capable for use in an ATV.