I've been having this conversation a lot over different forums and it's one I enjoy because I love hearing contrasting opinions.
As quite a few already have said, I feel Cherami Leigh's performance is just leaps and bounds above Gavin Drea. The more I converse about it, the more convinced I am that her experience is really what sets her apart. I have two main reasons for my thought process and thats:
1. Her V suits any of the 3 Lifepaths - maaaaybe corpo being a slight outlier here, but not by a huge margin, IMO I think her perfomance works for any of the Lifepaths. I definitely cannot say the same for Gavin Drea.
2. Experience aside, I think he was given very poor direction. The accent, the tone, hell even the register he's sitting in, just doesn't feel right - its like they told him "be more gritty! more MANLY MAN!!" and he went just a little too close to the solid snake spectrum of grizzled. I've even gone as far as to say it feels like she was given a script with more context than he was. But AGAIN, that could be the experience factor. Like an experienced VA knows what questions to ask to get what context for the scene. Who really knows here.
EDIT: I do feel genuinely bad for the guy, because I respect Voice Acting as a profession so much, but it's really just...not great. And as I said, it could very well not necessarily be his vault. I read somewhere that in early trailers he was using a different voice and the internet did its thing so that's how we ended up with what we got. If anyone can confirm or deny this it would be appreciated.