The simple answer is "Yes, direct O2 injection is worth the money" but the more important question in my opinion is "Which kit are you wanting to buy?" Each one has their pros and cons. Personally, I don't use the red disposable tanks, instead I use a big oxygen tank meant for welding. They are cheaper in the long run because just one will last almost forever by brewing standards. However, I already had that bottle so it wasn't an extra expense for me.