We went through this last summer, and honestly, I spent way too much time researching triple-pane vs double-pane. Ended up going double-pane because the cost difference was pretty steep, and from what I gathered, the energy savings weren't dramatically better—maybe another 5-10% tops? Noise reduction was tempting though, especially since we're near a busy street. But even with double-pane, the improvement in sound insulation was noticeable enough for us.
One thing I didn't expect was how much the frame material mattered. We chose vinyl frames for budget reasons, but now I'm wondering if fiberglass or composite would've been worth the extra investment long-term. Anyone else notice a big difference there? Also curious if anyone's tracked their actual savings over multiple seasons...I keep meaning to do that but never quite get around to it.