It would be the base of experience or just purely an opinion but for me, Greediness is something that would really make us cripple.
"I want to bet more and more in order to win more. I will sell my properties so I can bet huge. " Greediness mindset keeps on the winning side, not satisfaction.
But addiction is a little disastrous, why? Because they can be satisfied with betting a small amount, at least they can gamble.
However, both can possibly happen in our lives when we can't control our gambling habit anymore. I prefer not the two but in this situation, I prefer to be just addicted rather than be greedy.
Gamble Responsibly...
Greed is bad and addiction is bad, there is no need to even compare the two together, they are both bad for gambler. As a gambler, if you have too much greed in you, there is nothing you might get from gambling because even with simple gains, you will want to apply greed which can obviously make you lose everything and as too much greed makes you lose money, you might be tempted to make back your losses because of that greed and you might be addicted in the process.
If you must gamble, do it moderately, don't be overwhelmed with greed and give limit to how you gamble and when to gamble, limiting things in life helps you a lot, this not just about gambling alone, it's a principle about life and it good practice for every gambler that want to go far in gambling, reduce greed and don't become emotional about it.