Luai is definitely a good player.
Actually, he is a very good player. He has shined in the Penrith team and has been a huge part of their success. I don't want to diminish that in any way, because although he's a merkin, he has created a wonderful resume and had success that other player could only dream of.
However, when it comes to playing talent, I believe Brown has a higher ceiling that Luai does. His strength and speed would be above Luai's, and even though Luai has become a good defender, Brown has him covered in this area as well. Their long kicking games might be on par (i.e. not all that great), but maybe Brown's short kicking game is slightly better.
On-field smarts, you'd have to give it to Luai at this stage. He has a lot more experience though, and Dylan has the chance to do a lot better in this area.
Leadership? I saw some have laughed at the notion of Luai being a good leader in this thread (probably mostly due to who said it), but Brown has shown nothing to say he is anything close to a leader, certainly not on the field anyway. Lui has at the very least the ability to rev up his team, add a sense of enthusiasm during games, and not look bored (which is what Dylan has been accused of many times).
If I was starting a team tomorrow and had a choice between Brown and Luai, I would pick Brown. A lot of that is because his price tag seems to be significantly lower, plus he is younger with the ability to get much better. Luai has reached his peak and is now very expensive. I think it's a pretty easy option tbh.
But, I may be rather biased. I'm sure a Penruth supporter would read this and laugh in my face. I guess we should ask some neutrals what they think.
By the way, I accidentally misspelled Penrith above. I was going to change it, but I thought it was funny, so left it in.