I would always prefer to use the original creator software to handle models - as long as it can do that. Only when that is not possible i would look for something else. I think Sketchup should be able to clean and smooth meshes, therefore i always would go for that first. As Gebe already said, it is inportant to know what export format you use from Sketchup.

One day your ship comes in - but you're at the airport.