I'm going to get a m4 for my 05svs. The standard slip-on is $260 at pipe city, $30 more I can get the titanium midpipe with it. There has to be a reason to get it with the mid, is it performance, ease of install or what? If it's just performance it can't be much. If I get it with the mid, can I install the header later? Any input would be appreciated.