I've had a delphi rep come in the shop and talk about their products. I've also had a guy from GB remanufacturing come into the shop and talk about his products. Both guys were great, knowledgeable, and had confidence in their products. Both places re-manufacture injectors and other diesel components, and both are normally cheaper then using motorcraft, but I still install motorcraft injectors. It's just something I've always done, and I've come to trust my reputation on that. R&R'ing injectors isn't a fun or enjoyable task, so I'm going to install parts that I've had positive experiences with vs something I have no experience with.
My post isn't meant to dissuade you from using them, by all means, use them. If it goes well and you save money too, all is good!
In my mind, I just can't afford to chance a repair on trying something different, when I've had no issues with what I'm currently doing.