MIDI loops are flexible and powerful allowing you to assign any of the musical phrases
to your favourite synth or sampler and is only instructional data, so you can change the
pitch and tempo beyond which the loops were originally recorded to any extent you like,
with no artefacts.
The WAV format is one of the simplest for storing audio information. The data is stored "in the raw" with no preprocessing. WAV files are uncompressed lossless audio and as such can take up quite a bit of space, coming in around 10 MB per minute with a maximum file size of 4 GB.