I like them smooth. The only Aluminum frame bike I've had like that was a 2006 Specialized Tricross Comp. It almost looked like a carbon fiber frame because the welds make the tubes look like they are all one part. Nice looking. My steel bikes are smooth also, but you can still see them. My Bianchi has a very small bead of weld around the tubes. Unless you look under the top and bottom tube next to the head tube. No weld there.... Italians......
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