If anything, the 740C is slightly better than the DacMagic, given the other electronics that are there besides the DACs themselves. Then again it's a CD player, so it has moving parts to go wrong, so as a DAC, it's six of one and half a dozen of the other. But as a CD player as well as an external DAC, I think it's worth the extra £50 over the 650C. As for the others, the CD6003 is very nice, I heard it the other day, plus it has the USB input, but I don't know if that's useful for you, I haven't heard the CD6003 use the USB input, but since you didn't mention anything about external DACs, I'm assuming that's not much good to you anyway.
But as just a CD player, the 740C is really good for the price, other than that I'd be unoriginal and say the Marantz.