Well, there isn't anything wrong with the 5305 if a high powered system is what you're after. While the eZee can accept more than a 20a controller with a switch out, it hasn't got the wiring to take extreme current like the Crystalyte can. Crystalyte motors have the most robust wiring of any hub motor i've seen. They will handle some seriously excessive current.
The 5305 is going to be more efficient in optimal conditions, but thats what the simulator represents. In true usage, the consistently higher RPMs of the geared motor translates to a higher real world eff. At a lower power output, you're going to get better value from the eZee, but as you have figured out, the 5305 has more high end potential. It all comes down to how much solar energy you're going to have at your disposal, and what your ultimate goal for the vehicle is, I suppose. The Crystalyte 5 series are certainly a choice pick for those looking for very high power potential.
I suppose one important factor would be finding out how much photovoltaic capacity you're going to have available as well.