Upcoming trip - 9/12-9/18; myself, husband, son (4) and son (10 months); park-hopper ticket. We've got reservations at HS for our first and last day, with one day reserved at each of the other parks.
I would love to ride RoTR and will try my darndest to get us a boarding pass in the morning on our first day. If we get them, GREAT! If not, we'll try again at 1pm. If we're still not successful, we'll probably try to hop to Magic Kingdom or another park for the rest of the afternoon.
Admittedly, though, I have a soft-spot for HS. Despite this being my 10th trip to WDW, I'm always shocked by how much fun I have at that park. I am not a huge Star Wars fan, but also know that this will be my first time at the park since Galaxy's Edge has opened. Between that and Mickey and Minnie's Runaway Railway, I have a lot of new things to explore.
While an extra day at HS gives you an extra chance to do RoTR, it also gives you another day to do Tower of Terror, Rock'n Roller Coaster, Mickey and Minnie's, Toy Story Mania (I could play all day until my arm falls off), and Slinky Dog Dash.