We're just on our 2nd session of agility, but this is how my trainer starts out. She trains for competition, not just for fun. The first level of the class I attend is all about teaching each piece of equipment. There are a few folks who are there just for fun, she doesn't do the same with them. If you express interest in competing, stuff is totally different. We do 2 - 3 pieces of the course each turn, and we do things slow. Things with contact points, the A-Frame, the dog walk, the table, she is all about slowing things down and making those contact points or in the case of the table, making them in the proper direction based on the handlers instructions. She will often thrown in a stop at the end of the weave to make sure that the dog is in proper position. She wants to train proper from the get go, not try and fix it after. So , yes, we do a sit at the end of the dog walk, but remember, she is not training at fast speeds at this level, we do a sit at the end of the A-frame. Everything is about making sure the dog is 100% trained on making contact points, following signals, and my part of the training is where to stand, which arm to be using, how to position my feet. I am not trying to keep up with Brodie, because that will never happen. I am training on where to be and how to move on the inside in the smallest, most effective way so I can direct him through a course, but remember we are not racing through the course at this level either, we are doing this slower and more methodical - this is teaching, not racing. If he is spot on and listening, at the end of the class, he gets a few full runs throughs without the stops. She does NOT want him to learn short cuts. Once we move up to the next level of class, we practice and pick up speed.
We had a border collie in our beginner class, she was FAST, she LOVES agility and competing. But she was trained elsewhere, was competing and never getting anywhere because she was taking short cuts. She started in our class to learn basics again, contact points, following her handlers instructions. She was worked these last two sessions with a contact point and clicker and after a lot of work, she is moving back up again.
If you are doing for fun, it's not as important, but if you think you want to try a few competitions (we did with Rally and it's fun!), you want to train correctly from the start because bad habits are HARD to break. Speed will come with practice, good habits will not easily be over-ridden.