That would be a tough trade for me to consider. I already have seven FAL's which I built to the spec's I wanted. I also have six 1911-types - with most of another from parts swapped out in earlier builds.
If this is a DSA built rifle I would not be concerned about reliability from the short barrel. They pretty much know what they are doing and I trust they would have done this right. If it was a home build then you might have to sort that out if it wasn't done right.
But if I were in your shoes I would do this deal to have both a long rifle and a carbine.