I just made a small table where I tested élastique 3.3.0 Timestretch Engine (I don't have time for all other Timestretch Engines). The sound source was an instrumental with loud drums and bass and instruments with long tones.
It turns out that the élastique 3.3.0 Pro with 0.0 ms fadesize and tonal optimized mode was the best choice for this special sound source and requirements. Although not perfect. Then élastique 3.3.0 Soloist Monophonic with 0.0 ms fadesize and tonal optimized mode comes into consideration.
https://www.dropbox.com/s/5bdqj32c12...ngine.pdf?dl=0
Maybe Justin could use that information.
edit: it actually seems that the élastique 3.3.0 Pro/Soloist in tonal-optimized mode and 0.0 ms fadesize is even in sync. not true
Sorry, it was late when I did that test and there are false testimonies.