Kyle,
For my money, Chechessee Creek is the best of the bunch. Very low profile, understated, and fun.
Secession is more about the experience than the golf...it's ok but not good enough to tear me away from any of the others you have mentioned.
Dye at Colleton River is fun regardless of green conditions. Unlike anything else around and very demanding when the wind blows.
Spring Island is beautiful, secluded, and worth visiting once-the golf course IMO does not measure up to Chechessee right down the road.
Practice facility at Berkeley Hall is world-class but the golf is pedestrian. Hampton Hall has some cool holes.
I was pleasantly surprised by Pinecrest across the street from Hampton Hall. It will never make anybody's Top 100 but it has some interesting holes (especially on the back 9) despite poor drainage-but every bit the equal of Berkeley Hall North design-wise.
The Marshwood (Tim Liddy) and Palmetto (Hills) courses at the Landings in Savannah are 45 min. from Bluffton and both are better than anything on HH island except Long Cove and Harbour Town-definitely worth the drive if you want to try something new.