This is a total guess - but if you've been at G for 5 years, Startup #2 sounds like a smoother transition. It's a larger organization, it will probably operate

This is a total guess - but if you've been at G for 5 years, Startup #2 sounds like a smoother transition. It's a larger organization, it will probably operate more like what you're used to. It sounds like both of these are good opportunities, and they both care about you joining. Carefully examine the real reason why you're leaving the comfy confines of G - that should push you closer to one or the other. Go with your gut.