I had heard the old ones were recycled cores however, I think the 1000's were excluded from that and are all brand new units afaik. I am running bosch 1000cc injectors and believe it's not so much the injector itself (provided you buy known brand names) but rather how they are setup. Multiple shops had a go at mine, only one produced results worth mentioning haha. It took a lot of time/effort to get mine to run right with them in place.

My cold/hot starts are generally fine 99.9% of the time although I do get the occasional hunt at idle which pisses me off a bit. It's not something that I will immediately amend but it will be done when I throw the front mount on.