I know I’m not wrong, I have done migrations to all of the vendors mentioned. Blesta whmcs never worked correctly and did not get resolved. Client accounts getting credits, invoicing not billing correct amounts, lots of stuff. Things like domain management, blesta doesn’t import correctly and was unusable (specifically RC) and is known, but that is seen as an RC issue and not the software.
For whmcs migration, upmind and clientexec were 100% accurate which is phenomenal.
I’m not beating on blesta, but feature wise it is lacking compared to upmind. Although blesta.club I think is making great inroads with that regard.