I love the telescoping arms and rear lift control on my Kioti DK65, it does make it too easy. But mostly, it's pulling drawbar implements, and I'm hooking up my older Ford tractors to 3pt equipment. I agree with all the advice I've read here, but would add that if your first alignment isn't perfect, you still just lower the 3pt ball that's nearest to a pin. I use a bungee cord between the arms if I need to keep them close together, lower the arms down on top of the pins before getting off the tractor. Turn off tractor, put lift in float detente, (or down, with tractor off), push or pull the ball end that best aligns with a pin to the outside and then push it on the pin before the arms go down too far. In most cases, both arms have to be pushed to the outside before they will start to lower down. Then you can use the lift arm adjusting crank to help you line up the other ball height. I just count the number of turns I've displaced it, then return it to where it was after both sides are hooked up.
I have another tractor that I bought used with the ez change system, but had to take it off since the weight of a 9 foot disc mower was too much extra torque with the added length in my mind. Also, not all my implements are standard width.
When you detach any 3pt implement that you can't lift easily with your arms, make sure to put it up on some blocks or something if it's not resting on ground when you set down the lift arms. Otherwise, you'll have to jack it up, or pry it up to get reconnected later.
If one ball goes on, but not the other, because of the ball link being too far forward or back, just get on the tractor and gently pull or push a bit to line it up, same with using the lift to help you align it. After the bottom pins are on, adjust the top link to meet the hole on the implement, knowing that you will have to put it to the correct length for your job after it's hooked up. Adjusting the top link is easiest when the load is just being set down and is taken off the center link. Watch the linkage as you take weight off of it, and shut down when it starts to show relief of pressure on the top link, then adjust the top link. Grease on the threads makes this a lot easier, too.
As Soundguy said, practice will make this easy and automatic. But there are still times where I wish I had a caddy for that awkward disc cutter hookup. Lot cheaper to buy adjustable, telescoping 3pt arms, though, and I'm looking at that for all my old tractors. Got a price of about $600 for each set of cat II from Kioti, hoping to find them for cheaper.
