I tried aluminum more than once but no more.
Sure, they look amazing but ...
Reduced signal. In my experience it's noticeable. At best it's minimal.
Not as much protection as you'd think. The best protection has some flexible material or matrix for shock absorption. Pure aluminum cases transfer the shock directly to the phone. Most cases do have some inner soft buffering but this adds bulk.
Case scratches easily. In order to preserve the sexy look you need to protect it from scratches. Over time just about every aluminum case looks beaten up - especially at the corners and especially ones that are colored.
Expensive. Enough said.
Any one of those is a potential deal breaker.
In the end it's not worth it IMO.