I have a New Trent something or other (couple of years old model), 5000mAh, one 1A output and one 500mA output. I'd guess that newer packs have more ooomph on the output.
Also have a Veho Pebble Smartstick, 2200mAh, one 500mA output only. (wouldn't have been my first choice given the capacity and limited output but it was a present, and it's really small so...)
Both working well