Good response, Thumper. Sorry for my harsh tone. I'd like to see your review of the ChipWerke PB. Could you repost it here, or send a link?
I'd only say that, comparing the price and hp/ft-lbs numbers of the Dinan tune to a Steinbauer tuning module (aka piggyback) they're the same. But Dinan offers the warranty on top of the numbers. And a tune will be kinder to your engine components overall. I'm not familiar with ChipWerke so I'd like to learn.
OTOH, there was a dyno comparo in the UK with bimmer diesels where the EcoTune came out way ahead of the Steinbauer, ACS, etc. for (what I think) was 50% of the price of the Steinbauer and 25% of the Schnitzer:
http://f30.bimmerpost.com/forums/sho...highlight=road
Here's the summary table:
None of those cars are the 320/328d but the percentages are still valid.