I own 4 Rough collies and 1 smooth collie.
Smooth Collies are actually just a Rough collie with short hair since Rough collies can occasionally give birth to a smooth puppy. But are considered a completely different breed nowadays. The personalities though are very different. Smooth collies can be more shy and snappy then Rough collies. My Smoothe Collie Jacks is just a puppy of 7 months but she is not snappy at all but can be shy with company. Their less matenience and are suited for city life.
Rough Collies on the other hand is a great companion.Their easy to train safe and extremly protective of children and a good watch dog. All four of my Rough Collies compete in agility and Sheep Dog trails (my smooth is in training for both) and they excel but all my dogs come from working lines. Most Rough collies are too overbred for the show ring. If you want a Rough Collie be ready for daily brushing two times a day their coats mat extremly easily and can beacome uncomfortable if not constantly brushed.
How much exercise do they need a day? Both breeds show be walked atleast two times a day unless you live in a rural area like myself and you can let your dogs out for a good run.
Are they good family dogs? Both breeds are great family dogs
Are they good with young children?Are they aggresive? The Rough collie is probley a better bet for younger children but s Smooth would do well if grown up with children at its side.
Would they protect you if you or your house was in danger?Or would they mainly just bark? Both breeds are extremly protective of their owners and property (all goes back to being sheep dogs) they are not GUARD dogs but will attack if someone was threatenig to you. Our dogs bark at everything not normal and it can get annoying just to let you know.
Lastly,how easily trainable are they? Both breeds are extremly smart and easy to obedience train.
Anything else you want to know I'd be happy to answer