I am guessing the 48 hole rim is better because it is more sturdy so other than that are there any advantages over one or the other?
I don’t think 48 spokes are necessary for any size wheel, and the extra weight and complexity are not worth it.
In theory 48 spokes will be better.
In reality, a 36 spokes are fine if the wheel is properly tensioned. Equal, proper tension is one of the most important factors in a strong wheel.
Generally I think that it would make sense for 36ers to have 48 spokes (then you can make the rim lighter and maintain strength, lowering the angular momentum of the wheel in the process) but if I were to do it again I would go with 36 spokes.
Why you ask?
The answer is spelled SCHLUMPF