Hey Bud,
My 220d has had EGR+Cooler Delete, remap for 210bhp and full turbo back free flow @2.5in ID.
I get 45mpg combined, after dyno the engine actually made 228bhp with 351ft/lb.
It delivers the same 0-100mph time as a 125d, its reliable and economic taking into account the performance.
If you have a 220d then the above upgrades transform the car in every way, im going to install a VB15 turbo with larger compressor and install a intercooler with 50% more surface area, after another remap it should make 240-250bhp if the head departs the block then ill buy a new engine and install deeper studs and better gasket.
Its a journey to bring the power up like this but in 2 years iv had to replace 2 injectors and a fuel pump so the stories of bad engine design are not true, its the emissions abatement that kills these engines i have found the 220d engine to be very reliable.