I never have any issues and am very happy with the product, service and price (CS never been an issue for me 😎) - but others may have had issues of course. Your contract runs for the sign up period you choose. These are usually 24, or 18 months. When it ends, you auto transfer to a new 30 day contract at a higher price. You can usually negotiate a better deal over the phone if you start a new 18 month contract with them - but it will vary and no guarantees.
One option that will provide the data is for you is to go ahead and sign up for the appropriate VM package and get it installed.
See how that goes - if its smooth and happens on time then its a good start.
On the day you activate it and first connect to the network is the day your contract starts. Run it for a few days and make a judgement/decision. You have 14 days of "cooling off" during which you can cancel the whole contract and incur no costs whatsoever and go back to your previous or another supplier
Whilst doing this, dont cancel your existing BB deal. Let the two run simultaneously for a few weeks - its a "cheap insurance policy" and will allow you to revert back quickly if the VM connection is poor.
Nothing to lose really.