I Want Everyone's Opinion on This...

[N-Man]

Costs.

I doubt life in jail is less expensive that execution. Consider that there will still be lawsuits and everything you mentioned even if the guy isn't on death row. I'll concede that just keeping killers in jail probably won't bleed the taxpayers dry though, so the point is pretty moot.

Forced Labor.

It just takes work away from your friendly neighborhood construction worker, imo. Maybe we could have convicts build large and physically stunning yet entirely useless things like the pyramids, or clean up radioactive waste or something, but it has to avoid taking jobs away from non-chainsaw murderers.

Wanting prisoners to suffer as badly as possible.

That, I just don't get. Let's avoid the repressed sadist in all of us, please.

(that everyone has rights, no matter if they acknowledge that in others or not)

I disagree. I think once someone kills, he declares he's not willing to play within the same set of rules as the rest of humanity, so we should treat him that way.