okay, looks as if the difference i can see is that the TFelectronics version is a modified version which makes it a true plug in.
Here are pics, as you can see the Vipec has a Nissan plug on the board and this would mean the board would have to be totally re-designed to do this.
This one is the TF Electronics board...
And this one is the link adaptor
So basically, TF are doing the same with the Link as what he was doing with the Autronic plug in's.. taking a ECU and engineering it to work directly with the OEM wiring harness - take the guts out of your ecu and put this one inside it and you have a true plug in.
So yes the nissan plug in's would be a different ecu, with the same software and chip. But the other wire in jobs, like the V88 ?? Who knows.
For me, the V44 plug in. I am going to bite the bullet and say that the extra price might be worth what your getting, But stay tuned.. we will see how it goes when i get my ecu soon! Then I will make judgement for sure.