Ive read somewhere that high flow catalytic converters are a complete waste of money, do virtually nothing, and are only worth buying with an exaust system if your current cat is rooted. Could someone please verify this?

Well so long as the current cat is not blocked and is modified to suit 2.5" flanges (another words flanges and piping are widened) then it would basically be the same. Not much different until you really start pumping exhaust fumes out such as at the drags with a turbo or supercharger.

Though I have a Hi-Flow cat sitting in my bedroom...I have not installed it because my old one is still running and I'm lazy. It is up to you if you want to spend the extra odd dollers for a hi flow cat. Just remember that you won't tell the difference.

that's my 2c

BTW anyone please correct me if I am wrong

Just put a hi flow 2 1/2 s/s cat on mine today. It had no cat on it for 1 day. It goes better and sounds better with the cat on. Yes mine was stuffed.