After about 3 years of existing. I am releasing version 1 of the Multi Ring Buffer Plugin.
With version 1 comes a few new features:
Non-doughnut buffer (regular):
Works either in a sequential manner by buffering the resulting buffer and differencing the previous buffer, or a central manner by buffering the original feature with different distances. Also by default the buffer dissolves the features before buffering.
Dissolving makes adjacent features behave in a better manner without overlapping buffers. The QGIS buffer feature has the logic behind this.
Issues and bug tracker: