Can't speak to the TA1, but can compare the ZAX to the TD06.
Sound signature:
The TD06 has substantially more sub-bass than the ZAX. Both the TD06 and ZAX feature a boosted mid-bass. Male vocals are more recessed on the TD06 than on the ZAX. Treble extension is substantially greater on the ZAX compared to the TD06. Overall, the TD06 is warmer and more visceral than the ZAX, but the ZAX is more balanced and has more sparkle than the TD06.
Imaging and Soundstage:
ZAX eats the TD06 for breakfast, lunch and dinner. The TD06 has a relatively confined, just-past-your-ears presentation while the ZAX allows the music to happen around you. Consequently, imaging on the TD06 is limited to discerning whether something is occurring on the left, right or center. The ZAX allows for a sense of airiness, as well as more spatial cues and instrument separation.
Detail retrieval:
The ZAX also slaughters the TD06 in this department.
Timbre and Dynamics:
The TD06 claws back some points against the ZAX here. The TD06 has a rich, natural and full-bodied timbre, whereas the ZAX does admirably for a hybrid but can present some artificiality at times.
Note weight is comparable across the TD06 and ZAX. The ZAX presents a sharper, more precise attack on each note than the TD06, but the TD06 presents a slower decay on each note than the ZAX. Overall, the ZAX is cleaner, brighter and more resolving than the TD06, but the TD06 is deeper, meatier and more intimate than the ZAX.
Usability:
The TD06 sports two tiny pinhole vents, encloses the driver in its own chamber with a sound tube, and is designed to sit flush and secure in one's outer ear. The ZAX is semi-open and its shell design prioritises universality of fit. Rather predictably, isolation is far superior on the TD06 than on the ZAX, and its bass-forward V-shaped sound makes it virtually perfect for commuting on the subway and on buses, since lower frequencies are usually the first to be impacted in such environments. For general listening, I gravitate to the ZAX most of the time, but might pick up the TD06 if I simply wanted to relax and wind down. The TD06 and ZAX are therefore complementary to each other for me, and I would hate to give up either of them.