Plus, as real life ion engines have burn times on the order of years, and as KSP can't do (adequate) time acceleration while the engine is running, there's a bi

Plus, as real life ion engines have burn times on the order of years, and as KSP can't do (adequate) time acceleration while the engine is running, there's a bit of an incentive to build high-thrust short-burn spacecraft --- I don't really want to have to babysit a burn in real time for six months. (This also disqualifies solar sails, which is a shame, because I'd love to play with them.)