Guys,
Your concerns are valid but have you seen the LBS MBA employment report??
Contrary to opinions this report mentions facts and numbers. With all due respect to the CEIBS/LBS fellow, he mentions his own experience and that's just it...I've been in the school and did not get that sense at all. Of course the LBS MBA students have to work hard to get a good job, but they do get them (non EU included)
When you go to an MBA there's a chance of not getting a good job but that's not a LBS problem exclusive. I know INSEAD graduates in the exact same situation.
Finally, remember that the rejected offers open up places for waitlisters. So if your turning down your offer, base your decision on numbers and not in feelings or opinions

PS: Nowhere does Oxford nor Cambridge have MBA brands at LBS level. HR managers know for goof the differences between the schools.