Hi,
Poly panels according to real life tests by a member of the forum do better with partial light, clouds and shading. The difference is one of size. The poly panels are slightly larger than the equivalent wattage Mono.
If and when I choose to upgrade it will be to poly.
The display on the Blue Sky gives only the output voltage and the output amperage. For more detailed information the IPN remote is required. That could be replaced by a $30 meter from Amazon or Ebay.
The Tristar display may give more information (I think). Tristar has a 30 amp model now.