Upstairs Too Hot or Cold? Batt vs Spray Foam Insulation

We're finally tackling the upstairs insulation issue - it's always either freezing or roasting up there, you know how it goes. Narrowed it down to batt insulation or spray foam. Spray foam seems pricier but maybe worth it for better sealing? Batt insulation is cheaper and DIY-friendly, but I'm worried it won't fix the drafts completely. Anyone have experience with either option, good or bad? Curious which you'd pick and why.