Some differences I see now are:
- The Italians are doing what I'm used to seeing, straight comb (even on a foundation-less frame), no burr comb between frames/on top of frames.
- The Italians are only storing nectar and pollen in the 2nd medium.
- The Carniolans have brood in the 2nd medium.
- The Carniolans will be leaving the hive when it is cooler outside, I've seen Carniolans leaving/coming into the hive while there is no activity on the Italian hive.
- The Carniolans are drawing burr comb on the tops of the frames and even between the frames. This makes it a bit of a mess.
It will be interesting to see how they progress.