Santi Bergen Base Layer versus Fourth Element Xerotherm Base Layer

[BFRedrocks]

Hey Guys,

Trying to decide between these two base layers for my DUI drysuit. I have the DUI Ecowear, but I want something with a little more thermo properties for when it gets really cold (to wear under my other undergarments), or for when it's not too cold (to wear alone). Most of my drysuit diving will be done in waters between 50 degrees F and 65 degrees F.

Any thoughts on these two base layers would be appreciated.

Thanks!