I guess that depends on whether.
a. you have the cash.
b. you're ready for them to introduce traffic management to the service later this year, which they will do (not sure what it will look like though).
c. you're covered by that particular service (all VM cable areas should be by this summer).
It does perform very well, although speeds of 30Mbps are probably more probable than 50Mbps, depending on what you're doing and other more technical factors. The big question is, can you benefit from the speed in your daily life? If you think it'll help and you have the cash then I guess the answer is yes.