I'm sorry if I gave the impression that the MSc Econ is *not* for people with PhD aspirations. Relative to the MSc EME it is less hard-core, but I think it's not at all true that somehow this is a lightweight programme. I think the previous commenter and perhaps myself were being unduly harsh. I do have a concern that with the changes to the programme structure, the MSc Econ in particular will be downgraded in its reputation.
We were making comparisons at a very high level- with the reference point being the first year of a US PhD programme at a strong department.
The MSc Econ is definitely still a stronger programme than the sorts of terminal Master's degrees offered in the US. In the US, a terminal master's programme is for people who will never be PhD material. Over there if you have a good background you go straight to a PhD where there is typically 2.5 years of taught coursework. I am not sure that outside the top 25, the level of students in US PhD programmes will be higher than the master's courses at LSE. I say this because based on experience it seems to be very tough to crack the top 10, quite tough to crack the 10-25, and then seems to get a lot easier. The UK master's courses at the top places are of a very good standard, closer to the first-year of a US PhD than they are to a US terminal master's.
There are *lots* of very bright people in both MSc Econ and MSc EME. But the very high quality is more uniform in the latter programme.
Remember: people who have done the MSc Econ have been accepted into the PhD Econ at LSE on the same basis as people who've done the MSc EME. Furthermore, in the past LSE has not required much further coursework beyond the MSc-level. So the MSc Econ in and of itself has been considered perfectly adequate core training by the LSE (in the past). There is a huge long list of famous economists who "only" did the M.Sc. Econ!
Furthermore, the record of those who have gained distinctions in either MSc Econ or MSc EME is outstanding. In my year, people multiple people went to MIT, Harvard, Stanford, Princeton, Yale and of course continued at the LSE. This was as true of Econ students as of EME students. I took classes with EME and Econ students and the two best students in all my classes were M.Sc. Econ- albeit taking all the "level II" classes. I think one went to Princeton and the other to Stanford.
From the perspective of going on to a US programme afterwards, the "level I" M.Sc. Econ classes are preparatory. They will give you a much better background than say the background provided by a US undergrad degree. But you will still need to learn new stuff. The EME classes, however, will put you in a position where you can afford to focus on perfecting your skills, rather than having to hurriedly acquire new ones.
I seriously doubt that anyone who has completed either M.Sc. at the LSE and got a distinction or even a merit grade will struggle in the first year of a US PhD programme. The difference is that EME graduates might even find it quite easy. So either choice is a good one to have.