Just take a quick look at the current state of your car and where you live. If you:
-> are lowered 1" or more
-> use smaller diameter tires than stock
-> live in rainy conditions with many street puddles
then it makes sense to get the Nismo cai for the bypass valve alone. Some have actually fit an AEM bypass on their AEM intake, although I bet the final cost is always higher than the Nismo.
Otherwise my AEM runs solid after 40k with one filter clean/reoil at 30k. Still looks and performs like new. Many here will back me up on this...as long as you install it correctly, regularly maintain the filter, and periodically check the couplers and brackets. More importantly, I drive the CRV during extremely rainy conditions.
And if you have to ask, don't make your own intake system. You risk damaging the MAF sensor ($500...yay!) due to vibration or excess particles. Thankfully the words "dryer vent hose" didn't appear anywhere in your query