We arrived on Koh Lanta in early May, stayed for 4 nights and found the island to be near deserted! Only half the shops were open and most tours weren't operating anymore due to the low season commencing in late April. Our resort looked great on the net, not quite as glam when we got there. We booked a beachside bungalow which was right on the beach, great location but quite run down. Ants were quite a problem and anything sweet will be devoured in 5 seconds flat. Also beware of open bottles of drinking water, not sweet, but the ants like it anyway!!
Due to being the start of the low season, the restaurant wasn't always well stocked and at times our breakfast options were few. No bananas one morning, no muesli or yoghurt another morning, and the staff didn't appear to care much about it.
Communication was quite difficult with the reception staff, even for basic things.
Pool was great, beach lovely although rocky in parts due to low tide. About 5 minute drive to Saladan, the main town centre. Not walkable unless you are keen on a 30-40 minute walk in the heat and humidity.
If you hire a motorbike, getting around will be heaps easier. We paid 250 baht per day. While we were there, the thai police were out in force, fining people riding bikes without helmets, us included!! A hefty $4 AUS fine. Only the driver is required to wear one, and most of the thai's don't seem to bother a lot of the time.
A beautiful island, but would have had a bit more to do if we were there during a more popular time. 4 nights was probably 1-2 nights too many unless you like to feel isolated.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.