||On a personal level, I'd never buy a commercial bank. Nor have I even bought a vocaloid or any other styled bank||
On a technical level, there needs to be the obvious:
- Otos
- Voicebank configuration type (vcv, cvvc, ect.)
- Language capabilities
- Voicebank quality
- Usage quality with any given resampler, or utau version
- Difficulty level on how to use it
- And appeal(design ect.)
But I think a lot of people are overlooking some other key factors of what a successful voicebank would be, such as (yet not limited to)
Does the voice sound unappealing, is there issues with pronunciation, does the tone sound like a dying frog, is it too breathy vs too strong, is there not enough tone variety available for download
Is the voice provider an actual singer, are they known for singing/appearing in any sort of media, are they known for something else within the community like making music-working on programing, are they musically inclined. What do we know about them?
Basically, the opportunity cost of making a commercial utau bank is not in the favor of most, if not any user. Seeing as you're essentially buying a bank from someone at random, who isn't
professionally working with any type of music branch, for a program that has many many many high quality voicebanks for free, and is also not that reliable compared to other programs. (no quality control, that's not a company, it's just a user)
"with vocaloid there is a degree of quality control set up by the company and a standard to go off of. when it comes to utau, there wouldn't be any set quality control for banks, and the already existent standard applies to non commercial banks and is of a much lower quality than those would expect to pay for something"
With that being said, you better bet this voicebank is voiced by someone I love, cherish and listen to on a daily basis.(Meaning it better be a nice sounding voice) The bank better be as high quality as possible, work with everything I throw at it(resamplers, languages ect.), be available as a hard copy, and have quality control and a reliable source. I'm not just about to spend money on just anything. Hope this long and possibly redundant reply was helpful