Freelander 1 Ronbox/Synergy - anyone running one - Td4

Curious on peoples experiences with these on the Td4. I have a Ronbox that I had on my 2.0d X-Type. It was a used Ronbox, and never thought it made a huge difference. But it might have been the car.

I can get the Ronbox plugs changed to fit the Td4 for £34, which is a lot cheaper than a proper remap. So I'd like to know how people have got on with them.

A proper remap is better, so giving better improvements in power and economy. The RB has the benefit of being transferable between vehicles.