It's awesome to have a powerful AI English bank! She'll expand what people can do with SynthV significantly, and compliment the banks specialising in soft performances. More than any other English vocal synth, Solaria is a product of the fandom's efforts, so it's great to see her come together successfully.
*edit*
She's definitely a vocal that excels in the high range. Emma Rowley herself describes her voice as high pitched, so I hope people take advantage of this strength. My one concern is that the fandom often conflates 'mature' with 'deep'; but a voice sounding obviously like an adult isn't automatically an alto, or suitable for that style of singing. I think voices that excel in low ranges are the last big gap Synth V English has left to fill, so I hope Solaria gets a friend with a deep voice soon!