I'd be very interested to see how far both parties take it. I think the assumption is that only Trump/Conservatives have and will be fact-checked, however this has already shown to not be the case. If anything, I'm sure Trump's calling out of fake news in the last 5 years has had a part to play with taking this action on the platform and should be classed as a positive across the board if implemented correctly and fairly. I like Dorsey, I thought he presented himself well after the two Rogan podcasts (would recommend if you haven't listened). He accepted back then that they would have to look at their policy where evidence was gathered showing harsher punishment on conservative posters than that of left-leaning posters, and he's done this.
Re: Twitter itself, I have an account but I find it difficult to scroll through regularly as it can escalate into a hotbed of vileness very quickly. However it is incredibly useful for breaking news, fact-checking through reputable and informed means and literal laugh-out-loud content.