The independent reports in the links below provide end user testimonials and statistical analysis comparing bailers with low flow pumps.  Both articles indicate that low flow pumps are useful in very specific applications but are more costly and time consuming to use than disposable bailers. 

    Pollution Equipment News - Disposable Bailer Preferred Alternative to Pumps

This report by William E. Lee III (Ph.D., P.E.) featured an in depth comparison of bailer and low flow groundwater sampling protocols.  The study provided guidelines for proper technique when sampling, and contained statistical data on the extent of water sample aeration using bailers and low flow peristaltic pumps.  Since the quality of a test sample is adversely affected by aeration and volatization, the study was trying to determine which sampling method produces the most accurate results.  As detailed in the tables below, the dissolved oxygen (DO) increases in samples using both methods clearly shows far less aeration is created when sampling with a bailer versus a peristaltic pump.

The analysis  in the study clearly demonstrates that bailers provide cleaner test samples than peristaltic pumps when used properly.  For more detail on the study please link to the reports below:

     A Tale of Two Samplers - Part 1

     A Tale of Two Samplers - Part 2