QTP-Downpipe

Ok so I am starting to get money together to do Mods and am going to be moving to CA in the next year or so, looking at info on socalevo.net I have learned cops in CA are dicks so instead of doing the AMS TBE i was thinking about I was thinking of doing this http://www.quicktimeperformance.com/Downpipes/evodp.php what do you guys know about this type of thing performance wise in comparison of a TBE also would it be possible to tune with the flange open would it be crap while normal driving and would it mess up smog Thanks