Vodafone mail (242) vs voicemail (121)

I'm thinking about switching from the usual 121 voicemail to the 242
service as this would allow me to receive voicemail messages in my email
while travelling and avoid the costs of calling into my voicemail
account from abroad. (I understand it would also provide an email
account and fax number that I don't need.)

Is the switchover straightforward? Has anyone had any concerns over
reliability?

Thanks.