Cauliflower gone bad? I've had a head of cauliflower in the frig for maybe 3-4 weeks . It's firm and not slimy. Is it any good?

The only problem it will of lost a lot of nutrients

The brassicas are a hardy lot. I'm still eating cabbages picked last November and stored in a cold shed. Brussels sprouts keep for weeks. This group of vegetables does very well in cold storage, aka your refrigerator.

If it doesn't have mold on the inside and not a lot of brown spots you are probably good to go. Cut it open and taste it and you will know.

Should be as long as it is firm and does not smell.

It should be okay. If it doesn't have mold and is firm.
I'd break it up..and give it a long soak in a big bowl of water with some white vinegar to help refresh it.