I have a choice of pool stores to walk in and have my pool water sample periodically tested. 

One store uses a digital process with a LaMotte Waterlink spin touch Lab digital machine.  The other store uses a combination of strips, stirring beakers, drops, etc.  I do not know what the process is called, but I have to ask for extra tests like:  Phosphate and salt level,

Both processes come close on PH, salt and Free CL levels.  They vary quite a bit on Alkalinity, Hardness and Stabilizer. 

Lamotte does only Free CL; the other, does Total and Free CL.

Which method is the more accurate choice?  Thanks.