A Matter of Opinion
I purchased the then named Time Machine back in the day and found after a few builds that it was extremely reliable and continue to use it to this day.
As a Pc technician and business owner I test a huge amount of software daily and only ever install software that is vigorously checked over time on my personal computers.
I found that flashback early builds,although clearly built on the former was not as good as it's predecessor but to be fair software does take time a lot of time and money to develop, tweak and perfect as best as possible.
while we mustn't lose sight of the fact that NO software is perfect it is important for those who develop to get a return for their efforts. As a consumer we expect software that is reliable and stable after all we are paying our hard earned cash for such software, I am currently downloading the latest build of Flashback from this site (703) and will test it accordingly. In the meantime I may place a copy o the cloud in due course of the most stable version of Time Machine for those who want a reliable version, that is of course if the authors do not object and that I am not infringing any copyrights etc.
Therefore I invite the authors to comment accordingly. Incidentally folks please remember, Software authors especially in this case are basically decent people so please bear that in mind before reporting negatively to them.