Up to you - everything has certain tradeoffs. These cotton gauze filters are no exception - they definitely require a certain amount of experience to get the most from them. With these filters - the only thing that is preventing dirt and debris from getting into the engine is the tack oil that is applied to the pleats. If you apply the oil incorrectly, it could have catastrophic effects. Where you drive the car can also have a huge impact on filtering performance as well.
That said - myself, I've never had any issue with my K&N aftermarket filter on the Corolla or any of the other cars that I've installed them on. I've even pulled UOAs with both a K&N and OEM filter installed and saw no appreciable difference in wear metals, silicates, etc. Fuel economy for me, has gone up a hair with the K&N. No change in HP that can be "felt" - just a slight audible change in the intake noise.
The key is making sure the filter sits in the airbox correctly (assuming this is a panel filter) and that it is oiled correctly. Too much oil - and it will increase the likelyhood of intake fouling (TB, MAF, IAT, etc.). Also can affect dirt capture - as too much oil is just a bad as too little, in overall dirt holding potential. Too little oil, or oil that has evaporated off - will greatly reduce dirt holding/capturing potential.
Washing the filter is pretty straightforward - drying will take some time. Oiling it - that is more of something you learn over time. With mine - I make sure the filter is perfectly dry before I oil them. Use the aerosol spray oil, way easier to apply, hit each pleat evenly, making sure to saturate the filter material evenly (go by the color) - after that is done - I stick it in a plastic bag and on top of some paper towels to allow any excess oil to wick away, give time for the oil to set into the cotton material. After that is done - I pop the filter in - never had an issue with that technique. In the mean time - I'll run the OEM filter. Since I run it only a couple days - that filter still looks brand new. Just check the gasket from time to time. Other owners run two K&N filters - swapping them out when needed. Once you oil the filter, you can toss it into a large zip lock bag, and it will keep for a surprising long time.