Steel vs. Aluminum vs. Resin

[ShelleyAnn]

Matt - We will be getting a 15' x 30' oval, so the uprights on the sides will mean all the world to the structure of the pool.

[matt4x4]

Yes, on an oval, your forces are different , that's why I put round in brackets, however, I doubt very much that you'd have problems with resin, especially uprights since the UV rays don't hit it directly to begin with because of them being vertical.
Just my 2 cents, but a resin structure really won't give you issues, even over the long term - wall will still be steel and bottom track will Never rot or corrode out of resin.