Having lived in Malaysia where there are buketloads of private universities for less academically inclined/rejected students (and admittedly, being one in the UK - I got accepted in the UK for med, but rejected back home) and having friends who have indeed gone to such places, these would be the questions I believe UK students should be asking:
1. Acceptance of qualification - would there truly be no difficulties in having the degree recognized in any part of the world?There is no telling to the extent the GMC/Dept. Health would go to bend the rules/loopholes in EU regulations to prevent such degrees, if more and more UK graduates train overseas. Furthermore, thinking more broadly, how about international recognition? For a new graduate, the options would be to do carry on their training in English speaking locations. If they aren't successful in the few wholly-English speaking countries of the EU, then will they be able to at least try in other countries? For example, Australia? UK may have to recognize EEA qualifications at the moment, but outside the EU, you'll see very little recognition. What will Barts do in this case? Issue a qualification entirely equal to the London one, diluting the London qualification?
2. Dislike from professionals in the field towards EEA grads. Now... look at the posts on the top. You can already feel the hatred/distaste, perhaps even a sense of belittling from the UK medical students. People are going to know that UK grads from EEA schools, unless from very well renowned schools, are not going to be treated as well as as a UK-educated one would be. Even if it isn't now, again, don't forget that this will be true by the time the first batch graduates, with increasing number of UK medical grads rising through the ranks.
3. Cost-to-benefit. Medicine isn't what it used to be in terms of pay and prestige. Of course, it is still a very stable profession, with little unemployment, but it certainly isn't the old "omg, he's a doctor" kinda thing. Would there be any point in paying so much?
4. What happens should, (and most likely will) the partnership ceases to exist? This is assuming Barts would be working in tandem with another universitiy, as I can't envision QMUL having the fiscal resources to open an entire campus on their own. Which one would now be the "home institution" of the graduate?