Lakos separators work very well. I have used them for many years. However, the best solution is to have a well that does not make sand. Modern wells can be cased and gravel packed to make a filter out of the well casing itself. In this way sand never enters the well.
A Lakos separator above ground will filter out most of the sand before it enters the house but, the pump system still has to pump the sand, which will destroy the pump.
A Lakos separator that fits in the well and on the pump, will keep the pump from seeing the sand. However, the pump must be set a considerable distance off the bottom of the well. This reduces the available water stored in the well. Then the Lakos will also drop the filtered sand to the bottom of the well. Eventually the sand will fill up the well and you will have to pull the pump and bail out the sand.
Without other options the Lakos is a good choice. Although spending a little more to have a well drilled that does not produce sand is by far the best option.