I've had a Fluke 771 for quite a few (~10) years, and if you can afford it I'd highly recommend it. Very handy and great reading resolution and accuracy for a low current clamp meter with 10uA resolution and 0.2% accuracy. It is difficult to make a decent low current clamp meter, and you want to look after it and keep it from large magnetic fields. All of which is why you don't find the higher accuracy on more general purpose models.
I also have a few UT 210E's clamp meters, but their DCA ranges are not good enough for process control with only 1mA resolution and 2% accuracy. UT211B is a similar, not sure if it does 0.1mA in DCA.
The Benning CM11 looks like a good compromise, with 100uA resolution and 1% accuracy. So the Fluke is an order of magnitude better - depends if you need that.
For further process control calibration & testing I've got a Mastek 7221 (oldest, ~8 years), a Mr Signal MR9270S (newest, ~1 year), and a few others. These are all handy but they're not clamp meters so require you to break the connection. Mr Signal particularly has extensive features, but that makes it a bit complex to use.
I don't do much process control stuff right now, but if I was buying again I'd maybe get a Fluke 773, and a Brymen 869S for everything else, with a plug-in current clamp for higher currents.