I have Mivv KA.0005.SRT stainless version, eBay Italy for 720 euros a year ago.
Build quality could be better, I had to smooth rough edges for pipes to fit into eachother and bend middle frame attachment point, nothing too bad thou.
End can is very heavy (2.6kg) in stainless and I quess titanium end can is therefore still heavy too. For my race bike (too loud for street) I replaced my end can with SC project M2 GP carbon can (only 0.7kg...2kg saved), diameter (60mm) fits perfecty.
KA.0005 comes with footpeg replacement bracket (aluminum sheet) and carbon can hugger-bracket, but without DB-killer. KA.0003 other way round.
KA.0005 has bit longer secondary pipes (good for midrange), KA.0003 secondaries are "normal" length.
Bottom line: End can is really ugly, but makes great deep sound, stainless is heavy, buy titanium only if you get great price advantage over alternatives.
Gen4 race: high spec.
Suzuki GSX1300R Hayabusa 2013: stock.
Kawasaki KX450F 2016: love it.