[SJFGTO]

1) Smell - yes it is there, bothers some, others not. Purely subjective. I don’t mind the smell, over time I rarely notice it. The benefit of no cats on a FI car with long tubes outweighs the annoyance.
2) Rasp - a bigger concern. Rasp is that rattle, slightly metallic sound under load. Some exhaust systems mitigate the rasp of a catless exhaust better than others. The ARH full length system is the most rasp free exhaust I have ever heard. Corsa systems do a pretty good job too.
3) Catless is worth 3-7 HP on most street builds that I have seen, not really a reason to do it.
4) Reliability- already covered in numerous threads. FWIW, I went catless because a cat failure is high risk catastrophic engine damage. No inspection where I live, so going catless just is cheap insurance.