Most printers that are called "laser" use a semiconductor laser (laser LED) these days to sensitize the drum via a rotating mirror. I don't know if there were "laser" printers prior to the advent of the laser LED, but if there were, then they would have used a "real" low power laser for the purpose. Okidata printers used to use a row of LCD "windows" (acting like shutters) that open to allow a strong light source (could be the same laser LED w/ mirror) to sensitize the drum - now they use an array of ultra-bright LEDs to directly sensitize the drum. Theoretically the Okidata system could be more accurate and reliable as it relies on no moving parts - the only limitation is on how small LEDs can be made for improving resolution. You'll have to rely on reviews and word of mouth to let you know whether the promise of the Oki technology is being realized in their products.
Plain paper and other thin stocks aren't phased by U-shaped paper paths. It's the thicker stock and labels that can be problematic. Most laser printers offer a "straight" paper path for special stocks (often one sheet at a time, manual feed) as well as a U-shape for normal paper (bottom paper cassettes). Many of the Canon Pixmas offer dual paper paths as well, with a bottom cassette for plain paper and other thin stocks and a fairly straight path from the bin that can deal with most any media - I have put 110 lb. card stock and even slightly thicker photo stock thru my iP3000 successfully. The spec sheet for each model will point out the paper feed options available on the printer. Just pick one to match your media usages.
.bh.