People who say that there is no difference between MPT and DPT are really thinking in the present. No one can say exactly where the field is going, but, while the MPT may be an acceptable and attractive option today, I think that may be very different in the future.
In addition, don't count on your future employer paying for you to get the t-DPT. I work for a hospital now, and one PT wanted to go from MPT to DPT and had to pay for it completely on her own. Any continuing ed course the PTs want to do (even 1-day courses for a couple hundred dollars) have to be approved, and about 80% are being denied because of budget cuts. Granted, this is influenced by the economy, which is ever changing, but don't count on your future employer to pay for your t-DPT, even if it is a hospital.