The Imod is more compact, convenient and portable. The turntable will probably enjoy a longer lifespan.
As for sound, it will all boil down to your preferences and requirements.
At this stage of the game, I would buy the Imod. At $400, you don't get much analog and the idea of getting started with good quality vinyl is a bit daunting when compared against the cost and convenience of downloading.
However, if you must have a turntable, I have just the thing for you. PM me, if interested.