Ah! The million dollar question (love marriage or arranged marriage?) in the garb of an innocent comment! A question, the answer to which, has not been settled even after years of discussion and debate. And neither will I fall into the trap of trying to settle it here!
But I will stick my neck out and say this much, and I choose my words carefully - consider two healthy marriages of 20 years, exactly similar for arguments sake in ALL aspects. If one of them was preceded by a courtship period of 2-3 years, then we have 22 or 23 years of relationship in that case as opposed to 20 in the other case. And personally, I would take 23 years over 20 any day.
So ultimately, I don't think it is the 'quality' of the relationship (which one is better?) that will differ in the two cases, but the 'quantity' (which one is longer?).