Those are pretty accurate estimates. If you map to the center of the Esplanade, the Element is .8 miles and the Springhill is .7.
https://goo.gl/maps/yRaS2ZWpW8jfD3AY7https://goo.gl/maps/1p9N7TfPJE8CpZy26
For the cost savings, to me, an extra .1 mile each direction isn't a big deal, especially since your party is all old enough that Uber and Lyft are viable alternatives to walking, in addition to ART (hint, as far as I noticed, the McDonald's on Harbor doesn't have a no Uber/Lyft pick up sign, so pop in to grab a drink at the end of the night and pick up your Uber/Lyft from there as a much more convenient option than the over-crowded drop-off/pick up lot). I think the issue is mainly psychological, that the walk appears to be longer because there are no landmarks along the way that make it feel as if you're getting closer until you hit Harbor. If it were just our immediate family (9 and 11 year old) I'd definitely be staying at the Element over Desert Inn and Desert Palms. Our issue is that my MIL has hip problems, FIL has back problems and we're also travelling with SIL/DIL who will have a 1 and 4 year old, so they can't use Uber/Lyft, which is why I'm thinking a closer option may work better for us, although Desert Palms is really only .2 miles closer and the Desert Inn, while close, very spacious and clean, has those dreadful hard beds, a mediocre breakfast and the super-chlorine laden tiny indoor pool.
Here's the ART route and schedule if you're interested in checking that out (note, they apparently haven't updated their map since Hilton bought the Country Inn from Radisson and turned it into the Suncoast):
https://rideart.org/routes-and-schedules/clementine-line/