Whole exome sequencing by high-throughput sequencing of target-enriched genomic DNA (exome-seq) has become common in basic and translational research as a means of interrogating the interpretable part of the human genome at relatively low cost. Presented here is a comparison of three major commercial exome sequencing platforms from Agilent, Illumina and Nimblegen applied to the same human blood sample. The Nimblegen platform, which is the only one to use high-density overlapping baits, provides increased efficiency of enrichment and sensitivity for detecting variants but covers fewer genomic regions than the other platforms. As a result, Nimblegen requires the least amount of sequencing to sensitively detect small variants, but Agilent and Illumina are able to detect a greater total number of variants with additional sequencing. Illumina in particular captures the untranslated regions, which are missing from the Nimblegen and Agilent platforms. Exome sequencing and whole genome sequencing (WGS) of the same sample were also compared, demonstrating that exome-seq allows for the detection of additional small variants missed by WGS. These data suggest that WGS experiments benefit from being supplemented with targeted exome-seq data. This study serves to assist the community in selecting the optimal exome-seq platform for their experiments, as well as proving that exome-seq is capable of identifying important coding variations that are missed by a typical WGS experiment.