Most tourists who come to Rach Gia are coming for the ferry to the island. There are two services a day: 8am and 1pm. There are a cluster of guesthouses that are next to the port that must depend on everyone who arrives too late for the ferry.
I actually wanted to stay in Rach Gia for the day and have a look around and the port area is also convenient to the centre of town without being a seedy port area.
The Kiet Hong was a nice hotel, especially for the price (I paid $10.78 USD). My room looked new and the bed was comfortable. The had a ceiling fan and air con.
The bathroom was clean and spacious (ie a separate shower area).
Free water is included.
What I liked about this hotel was the amount of travel information they provide. Guests are presented with a travel guide with details on how to get to Phu Quoc by ferry, and how to get to Can Tho and Ho Chi Minh City from Rach Gia. They also detail how to buy the ferry tickets, thus avoiding any touts that may try and sell you a ticket (I didn’t see any touts but good to know anyway). There is also a free taxi service, which would be useful if you are going to the bus station.
Granted the night staff barely spoke a word of English between them, so this at least covered all the questions that a visitor would possibly ask.
All up I was happy with my hotel selection at Rach Gia.