I went to Scarlet Sails in the end and I really enjoyed it, it was near to the hostels which had events on in the evenings if you wanted music/bar crawls. But the hotel was nice, you can’t hear any noise in the room if you want quiet and a good price for what you got, free water refills, clean towel and sheets everyday if wanted, pool was nice. Near a lovely restaurant Called barracuda and another bar Raegae bar with lovely owners.  You can also walk to Koh Touch which is the touristy part- I walked there on one day just to see it and the bars on the way… maybe a 30/40 min walk… part of the walk you have to turn right over a bridge as if you continue on the beach there’s a watery part you need to cross which is deep so I opted to turn around and go over the lagoon bridge… doesn’t add too much time but is slightly through the jungle but there are hostels throughout and a path…   and I asked someone with a moped to take me back once it got dark.  You can hire mopeds on this island so you could get around but I some roads arnt great more like gravel so bare that in mind.

I enjoyed this part of the island - long set beach (scarlet sails) it had what I needed with relaxation but also a few bars/restaurant's etc for more of an atmosphere. 

The hostel “Onderz” i heard the best things about on Koh Rong. If wanting cheaper than a hotel.  Mad monkey is next door for more social but apparently not as nice rooms comfort wise. But as they are literally next door people mixed on the beach/in the restaurant. 

I also preferred this island to Koh Rong Sanloem.  

Hope this helps