To be honest the sportster would def. meet your power needs and would be the better choice for the long trips, but on the maintenance side the shadow is the clear winner, plus you are right yours is paid for, so you could put the money you save in maintenance and not having a payment into juicing your bike.. i.e. power commander, K&n intake filter, and these mods would make your bike run smoother at highway speeds... so it's kind of a no-brainer I'd stick with the shadow for now, purchase some performance upgrades, and ride it till the wheels fall off....