I found it was pretty good, however, everyone in my type rating class had previous Collins avionics experience, so no one struggled with it. The instructors spent almost zero time instructing on the Collins avionics, so if you don't have any prior experience with it I'd imagine you may need to spend some extra time after hours to figure it out. As far as I recall, none of the ground instructors or the sim instructors I had during training had any experience flying the 350, but I still found them very knowledgeable for the most part.

I don't know if the 350 is more difficult compared to Textron/Embraer, but out of the 12 people that were in my type rating class I don't believe anyone failed the oral or sim. All I would say is if it's your first jet or you have never used Collins avionics before, I would not recommend the 350.