I am very concerned about maintenance, too, and we went with an Asian mahogany. It was slightly more expensive than cedar.

I figure that under the eaves is a well protected spot that shouldn't need recoating very often.

Be sure to paint your finish on all sides before you install it, it helps cut back on the maintenance needs.

Alternatively, aluminum is a common soffit material and is much cheaper than steel.

we love our clear finished douglas fir on our soffits and it requires much less maintenance than in other exterior areas.

Corten & Hardi then I would use this Atas system or something similar

Hardie

A soffit is protected from the weather so you can use just about any material with good results if you keep it properly painted. My home is a 32-year old home is in coastal Virginia. It has cedar siding and wood soffits. While the cedar siding involves periodic rot repair, the plywood soffits are in like-new condition.

The soffits are not as critical as the fascias. The soffit material should be rot resistant. The favored wood in my area is redwood or cedar plywood. These are then heavily stained and re-stained every 5 to 10 years. The fascia is more critical since the rain gutter rest on it and it gets wetted in rains. It is slow to dry under the gutter It is affected by heavy dew during high humidity periods. Redwood boards are favored by builders in my area. If a rot resistant wood product is not available, then use other rot resistant material.

To be sure, fascias and rakes are more exposed to the elements than soffits and call for different materials. In our area fascias and rakes (on either brick or sided homes) are typically painted. Cellular PVC is our material of choice because it won't rot and insects won't eat it.

PVC should be good and the woodpeckers will leave it alone. During a few spring-times, flickers used mine for drumming. Have you ever been awakened at 6am by a flicker banging away on the rain gutter and fascia over your bedroom? LOL

That'd be quite a woodpecker to hang upside down!