Hi,
My car is currently sitting on close to 180 000km, i have had Xcede Performance Software and X-Flow Downpipe (De-DPF) since the 140 000km mark. I did exhaust not too long ago. The car has received a clean health report from Tune Tech.
To answer your question, yes, it is advisable to do De-DPF (Downpipe) together with software. As, essentially, sw increases increments which creates more heat from the turbo. Hence, having the DPF removed, allows the heat to escape easily.
I know you PM'd me, and i ignored you. I apologize for that. You are most welcome to contact me, i am in GP and willing to take you for a drive and put you in contact with Xcede and X-Flow.
With that, the ultimate choice is yours. There are many tuners on this forum, but personally, i will only use Xcede as there recipe is proven. I might not have all the answers to your questions, but i can assure you Sherwin and Alistair will sort your car out properly.
PM on its way.
Thanks
Arbee