Looking at a rod that has standard, micro, and nano.  What if any are the benefits to non standard guides?  Any drawbacks?

I think there is sensitivity advantages, some say casting distance (debatable), lighter rod blank. 

 

Braid to a leader could be an issue. Icy conditions also may be an issue. 

I never use leaders so I use Fuji micro guides exclusively. I think they cast further. They are definitely lighter. And I think they make the rod more sensitive. If you use leaders they could be a problem.