Hardly any and I can tell you, if you have the LD340, it's an awesome intake. In fact, many believe the Performer RPM was derived from the LD.
It makes great torque on the bottom, but is not constrained in upper rpm band. I've ran them 7-8000 rpms and they always pulled hard.
I, personally, wouldn't spend a dime on another intake - unless it was for a dedicated race car, if I had the LD sitting on the shelf. Again, just my opinion.