"Lightweight" vs "Endurance" won't actually be that big of a difference. Depending on the specific bike, you could conceivably set up a Lightweight bike to fit like an Endurance bike, by fitting an extra couple of spacers beneath the stem (if the steerer tube is long enough), or by getting a stem that's angled upwards, and potentially shorter. As for weight, if you match component picks exactly between Lightweight and Endurance frames from the same brand, you're likely to end up within one pound of each other. Lightweight bikes are more likely to be fitted with lightweight wheels and maybe a slightly lighter cockpit (seatpost, saddle can make a bit of difference), whereas the Endurance bike might get fitted with more aero wheels and a more shock-absorbing seatpost/saddle combination.
A couple of things you could do to try different fits is to see if you can buy/borrow an adjustable stem. Some hybrids come with them, and while they're ugly and heavy, you can try tilting it up for a shorter/more upright ride, and tilting it down as far as you're comfortable with, and seeing how far below your saddle your handlebars end up being. If your handlebars are within about an inch of your saddle height, you're likely more comfortable on endurance-style geometry, if you can get your handlebars 2" or lower than your saddle (don't know if that's possible on your particular bike), then maybe something more aero or traditional racey/lightweight is more up your alley. Obviously not a perfect comparison, but could give you a general idea of what the differences could be.