I put this on my PW1 and adding to collections seems to be a little faster. The last update made collections almost unusable for me. It took 2 minutes to add a book to collections. Now it takes maybe 30-40 seconds.
I will check again later to make sure if the little more speed wasn't just because of the usual update reboot.
I haven't noticed anything else different at all from either 5.4.4 or 5.4.4.1
Pretty much the same.
eta: as to the dictionary question. I am not sure I understand that question. I have a scroll bar, I am on 5.4.4.2 now. I always had a scroll bar I am pretty sure, on 5.4.4 and on 5.4.4.1
I press a word and I get a window. I have no clue if that is a full definition or small window. I have no clue what either looks like. I hightlight the word gypsy for example and I get a pop up covering almost all of the screen. It shows dictionary and there are 2 more tabs called xray and wikipedia. There is a scroll bar as I have 2 definitions for the word. Underneath there are 2 boxes to press, Search and More.
Does that help?