I'm lucky enough to have recently bought a Memotron, with the Vintage Collection 2 expansion giving extra sounds, including two sets of Eminent 310U String sounds.
I admit that this thing is not cheap, however, the sounds are stunning and I would not part with it. My reasoning for buying it is that I have loads of Eminent/Mellotron sounds in software form, but it just doesn't excite me looking at a screen, I want keys and physical knobs and dials. Also, have you tried routing software Eminent strings out of a computer, through a small stone and back in again for recording?
I think the Memotron looks ace, and people who have seen it comment on it's looks, despite not having a clue what it is.
I know people are calling it a very expensive, if not overpriced ROMpler, but you are actually buying a replica Mellotron, and if it's a Mellotron you want, then with a Memotron, then a Mellotron is what you'll get.
The touch of the keyboard is one of the best I have and it is a joy to play. To me the whole experience of playing the Memotron is a joy. No software dials, no memory overloads, no crashes, just pure vintage Mellotron playing. I simply haven't got the space for an Eminent, so this is the closest I'm going to get.
One last thing, I don't work for Manikin, I just love this instrument (and it's limitations). My advice is if you can afford one, buy one.
Have a look here for some very short sample tracks I did using some of the Memotron/Eminent sounds:
http://web.mac.com/ipaul24/Jarre/Sample_1.html