Overall LTE is nice. A noticable speed boost doing "normal" things like MMS and syncing.
Speedtest showed 28/15 or so in Westmount the one time I tried it.
If you move around a lot I've found that the battery can drain quicker as the phone (s3) bounces from LTE to 4G. LTE is noticably worse at less than ideal environments (in the house/etc).
