TCSunbow X3 Summary

The TCSunbow X3 uses an OEM version of SMI's SM2258 controller, which is also used on the ADATA SU800 and excellent Crucial MX500. It's a modern controller with solid firmware. The NAND is the bigger question mark. It's very similar to the Team L5 Lite 3D as it uses 32-layer, 256-Gbit/die 3D TLC, but the sources are different; while the Team drive usually uses Hynix, the stuff on this one is from Intel.

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But we can clearly tell it's "second-sourced" (my term for it being NAND you won't generally see in top retail products) and is somewhat close to what the ADATA SU650/SU655 used to use before transitioning to Micron's 32-layer/384-Gbit 3D TLC. This is manifest in the lower sequential speeds which, truthfully, mean little to nothing for a budget drive like this as you will generally be bottlenecked elsewhere in the system in everyday use.
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UPDATE AS OF 2020:
Both the TCSunbow X3 and the SU800 made a move to Samsung 64L TLC NAND. A very notable improvement that makes the drive even more worthwhile for its price as of early 2020.

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That's a lot of technical details but it means that, really, the hardware is not as questionable as you might be led to believe, and this is a common configuration for "Chinese" drives. The real sticking point is therefore brand. Or more specifically, support for a brand. While Team is relatively well-known in the NA market at this point, it's likely getting good support from TCSunbow might be difficult.
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UPDATE AS OF 2020:
Though, its reputation has slowly grown over the past few months and is apparent that they as a brand have expanded upon and improved notably in the form of their website actually not looking like some college startup company as of recent. Future improvement in support is more likely as with its QC, though as of now there are no serious QC problems.