Interesting. I have a friend who did a research paper on the MPL, and when it was done (last summer), there hadn't been any upgrades to the LHS from MPL route guys. Although I originally put this down to the MPL not being around that long, it would be interesting to know if there have been any upgrades since.
When you obtain the ATPL at 1500hrs do you still have the same opportunities as other conventional ATPL holders?