I'm not a fan of either situation. I know there are people that use the wire method and the first thing I think of is what is the thickness of the wire, and do they ever scrub down the wire because it is still covered with urine and feces.

The problem with thin wire is the rats can develope bumble foot. Which is infected wounds on the bottom of their feet, which can be made worse by walking on the remnants of the urine and feces that are stuck on the wire.

But not cleaning their bedding and cages is simply inhumane and no animal should be subject to that either. The build up of feces, urine and ammonia is severely detrimental to their health.

So for me, both are equally wrong and unsafe.