I was actually curious to see if Ashra would do well with a prong collar after reading the positive feedback from you guys, and so I bought a secret powers collar (they look great, by the way). It didn't work out very well for us, as she was always on edge and more reactive when she had it on. Pulling / correcting herself wasn't effective - it had to be a very hard correction otherwise she would not pay attention at all and after a hard correction a few seconds later she would go back to doing the same thing. I didn't like that she needed such a hard correction so often, and so I no longer use it. I was considering just taking out the prongs and keeping it as a pretty collar, but it may come in handy with the future pup.
I currently use a 2" wide thick leather flat collar with a handle on it in case I need to restrain her. I've taught her to heel and that a small tug and jingle of the leash (there's an extra metal buckle for the sound) indicates to her that she has to come back to my side. I find this more effective than either a prong or a choke (I used to use a rolled leather choke, but it has since become ineffective... I swear this girl has developed extra neck muscles over the past month).
I should add that Ashra never pulled on the leash until about 8 months old when she decided to start testing boundaries, and so her leash education more or less started new from there.