I haven't read Sondland's testimony yet, I did read Taylor's in it's entirety. Pretty much, like I said before, Taylor has no evidence and the only support he can give for the quid pro quo is his conclusion that it "must have" been the reason for the delay in aid. He made a lot of "assumptions" about what was going on, most without any factual basis, and even where they did have a basis it was generally third hand or even further. Even damaging things he attributes to Sondland were often things that he was told Sondland said, as related by others, who themselves may not have been on the call. Literally, he's not an actual fact witness and nothing he said would be admisable in a trial.
The media didn't cover in any great detail that his testimony fell apart (and honestly stretched into questions of credibility, in my view) when they asked him directly about the Trump admin's concerns about Ukraine's interference in the last election. He was unaware that multiple Ukrainian official - some of whom are in the new government - directly intervened in the election, not least of which was the Ukranian ambassador to the US who penned a published op ed denigrating Trump. He flat out admitted that those activities were inappropriate, and seemed at a loss to explain why that wouldn't have been a legitimate concern of the administration.
The media doesn't point that out, because they've been pushing the idea that the request was about the NEXT election, notwithstanding that it expressly referenced the LAST election. So literally, they want you to believe that investigating interference in the last election (that factually occurred) is about influencing (illegally, though its not illegal) the next election. The vector on that is impossible to understand, so they just handwaive at "Biden" to pretend its all the same thing.
I'll eventually read Sondland's testimony as well, but unless he says Trump directed him to tell the Ukrainian's there was a quid pro quo, or can make a convincing factual presentation that this was a directive from Trump - even if unstated - he's actually useless to prove that Trump ordered a quid pro quo. As of now, my understanding is that Sondland now claims he told the Ukranians that there was a quid pro quo, despite the directions from on high that there was not one, because he "deduced" there must be one. Again, a lot of "deducing" and not much asking for clarification. But we'll see if it's clearer after I read the transcript.
If you have something better let me know, what's cited above as Lloyd Perna points out isn't proof that US policy was a quid pro quo or that Donald Trump ordered one, only that Sondland apparently now remembers that he thought there was one.