Let's assume we have a star spanning setting - a typical SF setting with space ships, wild electronic gear, armored marines, etc. What would be the most typical hand-held distance weapon? Laser? Electric shock? Tiny spin stabilized rockets? If you ask me, it's a slug thrower. Why? Easy to use, simple to make and maintain, self-contained, cheap, and deadly. But... but.. it's old-fashioned! So what! Good technology doesn't go away just because it's old technology.
What's a good model for transportation on an earth-type colony world? Anti-gravity buses? Sleek bullet trains? How about a prop-driven flying boat or amphibian? No need for infrastructure as it can land in any body of water, simple repairable tech, could be produced by the colony instead of imported, good range, and adequate load-bearing whether passengers or cargo. Colonies don't have established infrastructure like tracks and airports. They don't have extensive high tech manufacturing. Exotic materials may be scarce until their economy matures.
Instead of looking for flashy and sleek, let's look at sustainable, easily maintained, simple tech. Sometimes older technology is good enough, and sometimes it may be preferable in a different situation.