I have had mixed results with both collars with my dogs depending on the dog and the circumstances. Trigger absolutely hates a Gentle Leader and only barely tolerates a Halti but catches 3 ft of air straight up when he sees a prong collar so thst's what we use when walking him. Pongo only wore a prong to finetune positioning for a non-formal heel otherwise she is walked on a flat collar or a Halti (when my daughter walks her)which she doesn't seem to mind at all. Balto is walked on a flat collar now but did wear a prong for a while and does occasionally. Calvin and Hobbes it depends on what we're doing and where we're going. A prong made Hobbes' reactivity worse so I had to stop using it around other dogs espeically if they got into his reactive zone, if they were outside the zone, the prong(which was seldom needed) worked fine. As for the Halti, it is the only headcollar Hobbes will tolerate as I use it to guide him with two long lines attached to it like reins for carting along with vocal commands. The GL we had probelms with and he actively went on seek and destory missions to try to avoid it. Calvin doesn't care either way so if I need to use corrections, we use a prong but just for a relaxed stroll on a loose leash or carting training, a Halti or flat collar works fine.