I was just this week searching for a retopo solution in Blender(while pondering joining Topogun 3 beta)
After discounting Retopoflow 3 beta(don’t like it at all) I discovered a pretty great combination that covers most situations. 3 free addons that can work together:
Speedretopo - just as simple as setting up retop in Maya. Everything is ready to go in a few clicks, with some nice features. Also, using native modeling tools like grid fill, F2, bevel, knife, etc is a bonus.
Polyquilt - has come a long way, can be called from Speedretopo, and is very close in features to Maya Quad Draw.
Retopo MT - this can be invoked solely for its edgeloop contours tool.(can also be called from within Speedretopo)
All 3 of these together are the way to go for me. Keeps everything in Blender and no jumping to Topogun, or Maya just for QD.
You should give it a try. Very simple tools to use.