I ought to do a floow up post (especially as hutch locked down a dupe from Azzin)
I used Hullo on Voda for about 5 months.
+ves
It worked as a visual voicemail
Gave Push notifications on messages and missed calls
-ves
I experienced large delays between messages being left and then being delivered to my phone.
I got annoyed with having to delete the missed calls from Hullo and from the phone icon
It would take a long time from pressing the button to play before actually playing the message.
Summary:
In all honesty i have deleted it and i have turned my voicemail off. If someone REALLY wants me, usually they'll ring twice. If they don't then they were probably only trying to sell me something