I was a little dissappointed when I looked at IEM (IPX's Investment Trust) - it has a shed load of holdings all at the 2.5% of fund and below - a novice could have put together such a portfolio. It is very much like an index and indeed if you plot it against the S&P500 ($SPX) the perfomance is similar in YTD in 2006.
The MNE on the other hand is much more concentrated with some holdings >5%. I prefer such specialist funds that take an agressive approach and back some of its holdings rather than spreading the risk and exposure to individual companies (though I accept that some would prefer the IEM aproach).
At present, I hold neither - I prefer direct investment in the companines themselves (which in the UK seem to be mostly on AIM) but I have been looking for main market exposure for my ISA. MNE may fit that bill but we'll see. In my experience, funds never live up to performing in line with their sectors, so perhaps I'll keep looking......