I have both Hex2 and Silo 1.42 and would choose Silo.  Browse through the public Beta 2  WIP thread at:

http://www.silo3d.com/forum/showthread.php?t=6806

and check out what some really good modelers are doing with Silo.

As mentioned, version 2 is free if you purchase 1.4 now  (plus you can participate in the beta if you want.).