I have had a few through classes. From what I have observed they are great learners but can have slow reaction times -or take a while to process what they have been told. There was one in Norfolk that came to agility and trick training - he was great - but very steady.
I had one for 13 very happy years. He was a fantastic dog, totally reliable, quick to learn and very willing. He also had a wicked sense of humour and didn't tolerate fools gladly
The one's I have met have been slightly less energetic and not as full on about herding - but I have never lived with one.
I've known of 4 Smooth Collies, 3 (all bitches) are quite slow, but 1 (dog) is up for anything like a Border Collie, but I think he was an exception.
I am talkiing mainly in work context - they go round the agility course, but tended to stick with the owner. Nothing was particularly hurried just done in thier own time. Playtimes were a bit different - and, as I said, I have not lived with one.
Yes, I mean round an agility course too, they run at the handlers pace, not working away like a Border Collie.
I have two smoothies a bitch of 2 and half and dog 7months old. I find them fantastic to live with. Easy to train, very loyal, not as obssesive as a border collie who I also own. Only down side is they are all very vocal. I know of one who is very succesful at agility and obedience but if you want a dog that wins they are probably not as fast and focused as a border collie but much eaier to live with. I would definatley recomend them as a good all round pet provided you have the time to exercise and keep them mentaly stimulated.