I have a very excitable 70 lb boxer/catahoula mix dog that absolutely loves people. Add that to living in an upstairs apartment and you've got trouble. My boy can, and will, pull me along behind him whether I like it or not should he see anyone downstairs that he wants to go greet, and couldn't care less that he's pulling me down a flight of stairs in the process. Normally, that scenario led to one or more of the following happening: a) he got choked on a normal collar and leash, b) he managed to put all his weight behind a normal harness and get downstairs through brute strength, or c) I get pulled along behind him, suffering bumps, bruises, and sprains. This got to be very problematic for me as I always had to "screen" the conditions outside before taking a pup that badly needed to go. If there was someone outside, I couldn't trust my dog to remember his manners well enough to not try bolting downstairs with me being dragged behind, and there was always the possibility of it being clear when I stepped out, but someone coming out seconds later, and it was bye-bye Brindle. This harness, however, put a stop to all that. He can still pull, but the way this is designed creates the ability for you, the owner, to pull back far easier without risk of choking or hurting your dog. Now, when I take my dog out, if he sees a person he just has to say hello to, I can hit the button on his retractable leash (a definite recommend as the perfect partner to this harness,) and he gets stopped, forced into turning towards me so he remembers I'm there, and I can control him from then on. He might still be excitable, but the leash prevents him, so long as you're quick on the uptake and paying attention to your dog and what HE'S paying attention to, it prevents him from being able to bolt very far before being turned around and stopped on the spot before he gets too far and trouble ensues. Now, as I said before, a strong dog can, and a determined dog will, still pull to get to his or her destination, but this harness is well designed, strong, and I have very little trouble keeping my dog under control until the crisis is adverted, (i.e. cat leaves the vicinity or a person stops petting and goes inside.) I have also been able, with 100% success, to pull my pup away from people that just won't get out of the way on the steps (sitting there indefinitely) or who are so amused by my dog that they won't leave and keep egging on his behavior. This harness does help with that as well because, as stated above, it does still pull the dog to the side, forcing their attention back to you, and within a few seconds you can have your dog back to the task at hand rather than on the distractions. As a further plus in the harness' favor, whenever we run across a young child who wants to pet the 'big puppy,' this harness has kept my dog in control so well I never doubted the child would get knocked over by a jumping boxer mix. (And if any of you have ever had a boxer, you know they love jumping on every person they meet, even if jumping isn't required to get within face-licking range.) I've even been able to keep Brindle under control so well that I could give brief dog lessons to the kids, teaching them general demeanor cues to the ones scared my pup wanted to hurt them so they know how a dog looks when he's angry and when he's happy, and let the younger ones that run up and immediately try petting know that's a bad idea unless the owner says it's okay. So, to recap the pluses for why you should get this harness if you've got a big dog that forgets all decorum when people are around: 1) Keeps him/her from pulling you down a dangerous flight of stairs. Even been able to go down safely in rain, snow, and ice conditions. 2) Keeps dog under control and out of trouble (i.e. dog fights, running into street, ect.) 3) Protects other people and animals from your pet's exuberance 4) Well made, tough, hasn't ripped or had any damage at all in over a year's worth of walkings 5) Most importantly, you can correct your pet and pull him back to you without choking or hurting him with this harness. The bad, because you need to know: 1) The dog CAN still pull in this, and like all harnesses, they can put a lot more of their weight and strength behind a harness, though this one does cut down a bit due to it's design that causes their legs to cross and turn them. I have been able to hold him back when he was pulling as hard as he could, from a sitting position without being moved an inch. 2) If you have a retractable leash and something catches your pup's attention, when they bolt, even if you hit the button, you're still going to get jerked a couple steps, and if you don't have a good grip on the leash, there goes your dog. 3) In a situation like above, should they get going fast enough to jerk you, when you hit the button or pull back on the leash, rather than a gentle turn around, the dog will get jerked around, fly in the air a bit, and kind of do an involuntary back-flip. My pup's never been hurt by this, (at least nothing worse than his ego,) but it might be frightening for people not used to seeing this. I still highly recommend checking your dog out, however, when this happens just to be safe, especially if he vaulted on something other than soft grass, like gravel or pavement. 4) The front of the harness needs to be checked regularly. As I said, they can pull in this if they really want what they were going after, and it causes the front to loosen periodically, making it easy for the dog to step out of the harness without meaning to. For their safety, as well as all animals' and people's in the vicinity, you need to check and re-adjust every so often, so there's no accidental slip-outs and escapes. I really do recommend this harness for anyone with an excitable dog if they are prone to bolting, even just to greet people, no matter how great their manners might be otherwise. It will save you a lot of heartache and just aches in general to both of you. Oh, and for anyone who needs a bit of help figuring this thing out, snap the clasp that isn't the grey on the black version, or dark red on the red version. Slip that over the dog's head with the ring for attaching the leash facing you, and the different colored part facing down. Then just snap the remaining clasp across the dog's chest, behind their front legs. when you take it off, just undo the different colored part and slip the harness off, leaving the other clasp fastened. Makes it much easier, and the whole put-on/take-off only takes a couple seconds, which for a squirming dog can mean the difference between accident or no accident. Hope this helped.