I've met and worked out with both Chinese and Taiwanese soldiers. This is a single, unprofessional perspective but you might find it interesting.
Both countries do a sort of military training for their youth, but only Taiwan (last I checked) does a year of required service. That said, there are almost no actual combat vets in either country, and Taiwanese military service is basically "sweep gravel, peon."
BUT! The Taiwanese will come with far greater discipline, based on my experience in on-base gyms. Chinese soldiers spend their days derping around, playing ping pong, occasionally running around a track. Some of them get sent out to the fringes of the country to "suppress dissidents" but the majority sit around twiddling their thumbs (information told to me by privates, so, grain of salt).
Taiwanese soldiers, volunteer and conscripts, do seem to get a great deal more actual military training, in terms of equipment and exercises. And, maybe unrelated, but their general strength levels are way higher than their Chinese counterparts (like I said, I hung out in their gyms).
In any case, an invasion of Taiwan would "fail" by most measures of military success. China could probably nuke the island into Ash, or rain shells on it until there was nobody left to surrender, but there is a highly volatile generation or two growing into a distinctly "Taiwanese" identity. They were political enough to take over their own parliament buildings, while being supported by local businesses with food and water. My unprofessional opinion is they sure as shit would be an aggressively horrifying guerrilla force, especially because ~80% are already trained.