My boy cat loves his harness, once it's on, but it's always a small wrestling match to get it on him. He's fine and settles down and sits politely at the door like a puppy as soon as it's on, but the process of wrapping it around him and buckling it up took quite some practice and lots of time.
Tips that work for me: Fasten the body strap before the neck strap, and leave the leash attached to the harness body clip before you start, that way you can get hold of him again if he runs off with half the harness on. And make sure you know where his feet are, Sune would stick his feet through the harness in all sorts of directions before I got the hang of it.
Without the harness, he likes to door rush, but being a city apartment cat before he came to live with me, as badly as he wants to get outside, he's actually quite scared. So he is super easy to catch, usually goes no further than 2 meters from the door.
But it did lead to a funny episode the other day, when I was taking boxes out to the garage, and he came out the door with me, I figured I'd let him follow, see how he did. As expected he stuck to me like glue all the way to the garage, (a whole 20 meters, but it's a big adventure for him!) But on the way back to the house, a bird flew up from the bush and he delightedly sprung after it. Directly into a snow drift about a meter deep, which he promptly disappeared into.
He immediately bounced straight up in the air, the way you see baby gazelles do on nature documentaries, but he couldn't figure out what direction to go because snow everywhere he looked, so while I'm dying laughing, there is this huge fluffy orange boy sproinging in and out of a pile of snow, yowling like he was being murdered the entire time. By the time I rescued him he was shaking and shivering, and clung to me with his paws around my neck like I had just pulled him out of a shark filled ocean.
I think we'll probably put the walks on hold until springtime for now
Sune's big day out
has some pictures if you would like to see his harness though (from just about the last day of autumn it was nice enough to go out)