If conditions allow, use whatever makes the most sense based on $ and aesthetics,

If we replace them it would be just for aesthetics, the windows seem to be functional and water tight.   

I am just not sure how it will look after the roofers install metal coping etc there, or they would be careful about "aesthetic" details :)Exterior/wood is also deteriorating, but I guess a painter can scrape the old paint and caulk for waterproofing.

I will do shingles if steel does not look  right aesthetically.

I am repositioning an 8- Unit Apartment  (Photos Here )  In my analysis i knew that the property was being under rented & with capital & aesthetic improvements i could drastically raise the rents.  

Usually they were installed for aesthetics. 

Are you using the outdoor carpet for aesthetic reasons or does it serve another purpose? 

Every day, I disprove conceptions that aesthetic improvements are the most important to increase home values, and that efficiency improvements are too expensive to make.

I've heard pallet wood can have the same aesthetic effect.  

Updating the mechanicals are far more important that the aesthetic.