I did mine in November. Easy job, just loosen two bolts, slide the blanking plate in and retighten them. Plates are availible on ebay.
Hard part was finding a small enough tool to get down there without removing half the engine. Took me about 40 minutes, mostly becaues I was trying different tools and was a little unsure where it was supposed to go,pictures on the ebay site were good enough once I was looking at the gd and not fd instructions.
I got no engine lights so far, done 5000km. I switched to new winter tires at the same time, so I don't dare to say if economy is better or worse. I'm up to an average of 4.7l/100km the last four tanks(4.3 for all of last year). My old winter tires did a lifetime average of 4.6, but the new ones are a lot grippier so it might be them that are responsible for the full increase. I'm hoping it's the tires, in the winter grip is more important than FE.
Preformance is better below 2000rpm, less hesitating and a more predictable power output (above 2k rpm the egr is always closed). It did increase exhaust noise and decrease its pitch(throatier).
Edit: not an issue for you, but for posteritys sake: DPF regents have gone from every 500km(exactly) to an interval of 1500-2000km, so exhaust is now hot enough to do most of the cleaning passively. Took four active regens to clear the old particles out though.
Best 5$ I spent on the car so far!