Not to answer with a question, but, if you could get one for free right now which one would it be and why would you choose it? Your answer would be my answer to your question.
All jokes aside, either one will work. Being a dedicated ACR forum means you'll probably get more points toward the ACR of course but the only thing I can honestly say against an ACR is that it is still fairly new and BM hasn't developed its groove yet. It's a new platform without the benefit of years of folks working with it.
I don't know anything about the LWRC rifles, however their reptation precedes them. I have to many AR pattern rifles, that's one of the reason I picked up an ACR. Glad I did, my copy shoots well, egonomics fit me very well. Over all if I had to, I would buy another ACR.
But with that said, I have never handled or fired a LWRC. So I can't give you a fair opinion.
Good luck and I hope you pick one that suits your needs well!!
Why don't you write out the pros and cons of both. There are more accessories and the ability to customize the LWRC is greater than the ACR right now. But it is your money and you have to live with the consequences of your decision. You should really do as much research as possible on both platforms and then weigh the two.