Honestly, the first thing I thought when I saw your question was "Is it fully voiced or only on CGs?"
Because I'm working on a game that only has voices on the CGs and it seems to be working out pretty well.
If I were to PLAY a VN with voices... Yeah, I'd have to say it would depend on the quality of the acting and whether or not the voices "Matched" the characters.
For example, say there's a Kuroshitsuji VN...
If the Undertaker sounded like he did in the english dub of the anime, I wouldn't keep the voices on simply because it just does not match his appearance.... if Sebastian did though...
I probably would, but like everyone is saying it depends on the quality of the voice acting. Unfortunately a lot of English voice actors are...not so great. I'd probably just want to read the novel myself, without voices.
Like others are saying, maybe put an option to enable/disable voice acting, since some people might not like the voices.
Professional voice actors know what they're doing, but it's a matter of casting the right person. Inexperienced people in amateur voice acting forums are going to be hit and miss. Game voice acting has a bad reputation because publishers used to hire inept friends and family as actors to save money, which is a poor practice. Example: Chaos Wars https://www.youtube.com/watch?v=8pD83hmKjr0
Akaya Akashiya Ayakashi no didn't have voice over but the music and sprites and atmosphere where all just so wonderful that it really didn't matter to me. So yeah, I would. I'm working on a script right now that I assume will never have voice over, unless I find some really good actors. It's going to be a BL though, so I'm assuming not too many guys would audition to begin with.
Completed: Dreams of the Skies, Anton's Vacation, Luka, The Halberd and The Tiger, Rising Angels, Pyrite Heart, Rising Angels: Reborn, The Halberd and The Fox, VN Tycoon, RA: Hope
I honestly don't like voice acting most of the time. I'd rather just use the voices I have for them in my head. So, to answer the question, I would be happier with a commercial VN without voices that used the money for a good writer.