First of hello from 60 miles south. Are you stationed a Cherry Point? Damn swinging with the wing are we?...lol
A X-pipe is true duals, they just meet up at some point and cross. Yes it would adversely effect performance to take of a X-Pipe. You want a X-Pipe it helps with air scavenging to move exhaust faster out of the collectors. The faster you can get air in and out of a engine the more efficient it will operate and officiant operation results in more power and Tq. The effects of a x-pipe or H-pipe are usually only noticed in the lower RPM range.