After a couple hours of researching and testing other quiz plugins, I purchased the Watu Pro plugin yesterday and have been loving it ever it since. I had an inquiry relating to my specific use of his plugin, and he responded within literally minutes.
Within the 24h, Bobby has answered several emails and has actually made revisions to his plugin to try and fix my pesky issues (which were not the fault of his product but of a another plugin that I was using).
He has offered way better support that any other premium plugin I've purchased, and this makes the purchase cost very fair. He also entertains feature requests for future versions, which is really cool, and makes me look forward to future updates.
The plugin contains many features that have given me new ideas for my project that i wasn't even considering when I was originally searching for a solution.
I hope more people purchase this plugin so he can continue to develop this great product... thanks Bobby!