I prefer
Netta because the pronunciation is more obvious and it has more of a prickly, planty feel because the t's are pointy and it also looks like "nettle". I think it has a slight "old lady" feel (in a good way). It reminds me of
Hazel,
Hattie,
Harriet,
Hester,
Nella, Denna,
Della,
Henna, etc.