Plenty to see and do in Chora Sfakion. One of my favourite parts of Crete (apart from Plakias of course) and I always have a couple of day trips in this direction during a stay in Plakias.
It takes about an hour to drive from Plakias to Chora Sfakion and well worth it. Try driving up the hairpin bends to reach the Anopoli plateau with great views of the White Mountains and then a little further on to get to the bridge over the Aradena gorge. Or catch the ferry at 10.30 in the morning along the coast to Loutro which is only accessible by boat. Or drive a couple of km out of Chora Sfakion, park the car and walk 20 minutes along the cliff top path to get to Sweetwater Beach, one of the best in Crete.
Chora Sfakion is normally pretty quiet and laid back but gets busier when the ferries come and go, particularly at about 6.30pm when all the walkers return from Samaria to catch their buses home. Leave at the wrong time and you could be stuck behind a bus for several km.
Definitely well worth at least one visit.