Really, for that you should be looking at the reviews out there, rather than asking us to summarize them for you. Beware of features vs benefits. There may be a lot of features that add no benefit to your photography, and as such they will have no value. Videos from Jarod Polin perhaps for sports, Duade Paton for birds, - really, who you want info from depends on how you use the camera and what kinds of activities or subjects you prefer.
Look at Canon's own website that shows the new features. Consider articles from DPReview.com and reviews on You Tube do a search for opinions on the R5II - just beware of extremes of either praise or criticism - those are often interested more in selling their websites.
cheers, TREVOR
The mark of good photographer is not what they hold in their hand, it's what they hold in their head;
"All the variety, all the charm, all the beauty of life is made up of light and shadow", Leo Tolstoy;
"Skill in photography is acquired by practice and not by purchase" Percy W. Harris
