Sunrise villas were great. We are currently traveling around Thailand and a four night stay on koh samet was our first stop.
We had already booked four nights at sunrise villas before we left the uk, which is probably advisable, particularly in the peak season. However you may be ok to just turn up or give them a call, and you can usually negotiate the price this way. We paid 1000 baht a night and thought this was about right (we heard that some of the cheaper 350/450 baht rooms more in town get broken into frequently).
Our room was number 9, we had a stunning view across the gulf of Thailand to the mainland, the room was clean, the bed was comfy, the air con was superb and, unlike most places, you can leave it on 24/7 even while your out. There was a larder fridge, English plug sockets, a flat screen tv (not that we ever turned it on) and a wardrobe with a safety deposit box inside. They provided two bottles of water on arrival (I see someone has complained that water wasn't provided, which is true bar the bottle you get on arrival, however water is so cheap, you can buy bottles from the bar or in the shops for about 10 baht (just over 20p)).
We spent a fair amount of time lounging around there, it's got a cute bar which is reasonably priced and serves breakfast until about 2 pm. There was such a laid back atmosphere which suited us down to a tee.
One of the owners (tony) was there during our stay and the manager (Chris, who used to own it until about 6 months ago) was usually always around, if not there is a number you can call and he comes straight away (we wanted a drink at the bar at around 9 pm so called him and he came straight down and then kept the bar open just for us until we went to bed). We spent a fair bit of time chatting to Chris, he was a nice guy and offered lots of insights into what to do on the island, tips on avoiding being ripped off, good places to eat, and where else he recommended visiting in Thailand, very helpful chap.
They don't serve food in the evenings but it's not far to stroll into the main part of town and saikaew beach (about 5/10 min walk). It was actually quite nice staying a bit away from the noisy sea front and then you had the option.
Downsides... genuinely we could not fault sunrise villas, some people may prefer to be closer to the beach and night life but if you don't mind the short walk (which we didnt) then it's not an issue.
If we go back to koh samet on our travels or any time in the future, we would definitely go back and stay at sunrise villas.
