While I can't comment on the individual applications, I can give you
some guidelines for evaluating them.

- Look for a privacy policy.  Can they sell your information?
- Look at how you can get a copy of your data.  Say for example
  you lose your phone and move to one they don't support, can
  you get a your data back so you can manually enter it.
- Look at how you are charged (is it a flat fee, per phone,
  per backup, per restore)
- See if you can change the data over the web
- See if you can control the backup schedule, especially if the
  backup/restore process uses airtime
- Look for what happens if you lose your username/password/pin.
  The easier it is to get your data back, the easier it is for
  someone pretending to be you :-)
- Look at how easily you can share data.  If your partner also
  has the service, can you share contacts.  Can one of you make
  a change that you both see.

Roger