Difference between piggyback tuner & removing ECU?

Hello again, another noob question here.
I'm looking to put a light tune or performance upgrade on my new (to me) '04 Jetta TDI.
Been in touch with a local VW specialist here in Little Rock, AR (O'hara Automotive) and he suggested the Malone tune but said the turnaround was around 4 days or so since they have to remove the ECU and ship it to them to be re-programmed. But there is also a product from Kerma that is a physical unit that you plug into your car and upload the tunes from. (If there are any motorcyclists on here, it seems like this might be similar to a power commander?...I don't know, I'm largely ignorant of this stuff so far.)
My question is simply.....what is the difference? Are there advantages/disadvantages of one vs. the other? Any help in understanding what these are would be greatly appreciated!

Malone has something similar to the Kerma unit - seen it on their website.

Very early MKIV cars (like 99.5-2000) you did have to pull the ECU to tune, but 2002 and up at least are OBD-reprogrammable, based on everything I've read here.

Rob Mayercik said:

Malone has something similar to the Kerma unit - seen it on their website.

Very early MKIV cars (like 99.5-2000) you did have to pull the ECU to tune, but 2002 and up at least are OBD-reprogrammable, based on everything I've read here.

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Ok. So by the sound of it, removing the ECU is at least unnecessary, if not pointless altogether? If the Kerma or Malone plug-in tuners do exactly the same thing as removing the ECU and shipping it off for repogramming, I do not know why anyone would do the latter. If it's a piggyback system like a power commander on a motorcycle is, then it's not really re-programming the ECU at all.

bignastyweather said:

If it's a piggyback system like a power commander on a motorcycle is, then it's not really re-programming the ECU at all.

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It is not like that... they actually upload the tune to the ECU and then you take it off. [I think]

PS - There is a whole subforum on tuning and performance. Go there and read and read and read.

Yes Kerma uses a lot of the same things that we do, other than a sticker and encryption the two tools are the same. These handheld units are flashing ECU files and then they can be stored away somewhere, it's not like a piggy back system that needs to be left plugged in or hi-jacks signals. The piggy back systems are typically just falsifying a boost or fuel signal. They do not work as advertised and are not really comparable to full ECU remaps. They do not allow for the same kind of safety procedures, such as over-boost protection, excessive rail pressure, etc (I won't get into too much detail as I don't want them figuring out how to make worthwhile products).

We rent out handheld units, that eliminates the need for removing the ECU and any downtime.

belome said:

It is not like that... they actually upload the tune to the ECU and then you take it off. [I think]
PS - There is a whole subforum on tuning and performance. Go there and read and read and read.

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Perhaps I put this in the wrong subforum. Figured since this was a basic question about what the products were, that it might go here. But, duly noted. I'll search/post there with further questions.

Owain@malonetuning said:

Yes Kerma uses a lot of the same things that we do, other than a sticker and encryption the two tools are the same. These handheld units are flashing ECU files and then they can be stored away somewhere, it's not like a piggy back system that needs to be left plugged in or hi-jacks signals. The piggy back systems are typically just falsifying a boost or fuel signal. They do not work as advertised and are not really comparable to full ECU remaps. They do not allow for the same kind of safety procedures, such as over-boost protection, excessive rail pressure, etc (I won't get into too much detail as I don't want them figuring out how to make worthwhile products).

We rent out handheld units, that eliminates the need for removing the ECU and any downtime.

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Good to know. They're doing the exact same thing, but the handheld unit is more versatile in that it doesn't require labor to remove the ECU, and doesn't result in downtime. I think I'll go that route instead of having this local guy remove the ECU.

bignastyweather said:

Ok. So by the sound of it, removing the ECU is at least unnecessary, if not pointless altogether? If the Kerma or Malone plug-in tuners do exactly the same thing as removing the ECU and shipping it off for repogramming, I do not know why anyone would do the latter. If it's a piggyback system like a power commander on a motorcycle is, then it's not really re-programming the ECU at all.

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Except that sometimes plugging in dosen't work. When I had my '05 Passat and had RocketChip retune it after the glow plugs where changed he was unable to get the tune to work using the ODB port. He ended up having to pull the ECU and put it on his bench to get the tune to load.