The Dinan AD shows that re-programming at the ECU level is the best way to achieve a tune that works without harming the engine. Dinan is charging $1600 plus for a tune, ProTunes start at $500 and up and you will more than likely need an ODBII programmer on top of that. What makes the JB4 (Stage 1) in my case very attractive is the price and ease of installation. The reason I decided to fork over the lessor amount of money compare to other options currently available.
My plan, get a base dyno on the car with A/F chart. Install the enclosed aFe instake system and the JB4 Stage 1 and get another dyno run afterwards. If my tuner (doing tunes for nearly 20 years) determines this is hurting more than helping my car's overall health in any way I will pull it and return it, no harm no foul (just a couple $$ less in the pocket). I had a Dinan S2 installed on my E92 and thought it was fantastic! When I took my car into BMW dealership for a required ECU update they actually were able to save the Dinan tune and make the required DME changes without removing the Dinan updates. So, BMW doesn't automatically void your warranty when they see something outside OEM on the car, at least in my real world experience. If the JB4 isn't the right way to go I will spend the large sum of money again for the Dinan tune as I know from experience if does work well and no issues with BMW service afterwards.
BMS has been selling JB4 Piggyback boxes for a while with many good reviews from owners online. With that, I will give it a try and see if it does truly increase performance and not cause damage to my engine. For the low entry price and ease, I feel it is worth a shot. Will share my experience with everyone so you can add this owner to one of the long list of lore about Piggyback vs ECU tunes.