I'm an extremely happy "CPO" customer. I had very specific vehicle criteria and the BMW CPO program offered up an E92 that I'm still loving 4 years later.
One thing I like to keep pointing out is that while we can debate the pros and cons of CPO here, the public/market puts a value on it we can't discount. I like to buy cars that are ~2 years old (let someone else take the huge initial depreciation hit, enjoy some remaining factory bumper-to-bumper warranty). Remember that CPO transfers to future owners no matter how many times the car is sold. So if I want to sell my 3-4 year old car in the private market and it may be getting close to the end of the factory warranty, I can use the CPO certification/warranty as a selling chip. I wouldn't buy a modern used BMW that wasn't CPO and I know many others feel the same.
You 335 guys want to have your cake and eat it too... if BMW is able to game title branding on lemon buybacks as alleged (for HPFP and related issues which you insist are not a long-term concern) how on earth is a private party inspection going to help you get to the bottom of a car history? A 335 may test perfectly fine today but throw a $5000 fit in a few weeks. Who's going to chip in for those repairs, PPI or CPO?
07 328xi coupe SG/Dakota leather, 6-speed manual, sport/premium/cold
02 325Cic vert AW/Montana leather, 5-speed manual, premium/removable hardtop
93 850Ci Oxford Green/Parchment, auto
71 Buick Riviera, 455 V8 land yacht