SSI vs Hilton Head

Hi! Looking to get some opinions on a vacation to St. Simon’s vs Hilton Head. I realize HH is not GA, but very close. We are a couple in our late 20s/early 30s who likes lowkey, not much drinking, just restaurants, some beach time, and exploring. What are the pros and cons of each? Any preference of the two? Looking to go in May. Just wanting to do something different than Florida beach trip but yet still get in a little beach time. We do that trip another time of year. I have been to SSI as a kid but don’t remember much. We went to Hilton head for a few hours while visiting Savannah and really liked it.

Edit: would super love to hear from people who’ve been to both!! Pros/cons… also what areas in each to stay?