One main issue imo is that working with large PDFs is vergy laggy. I didn't test anything bettwen but PDFs with like 10 pages worked totally fine for me. No performance issues detected. But then I loaded an Ebook (PDF) with about 800 Pages into Goodnotes and working with that was absolutely painful. Not only is the writing very laggy. Sometimes Goodnotes "swallows" my writing and just draws a straight line instead. But also the scrolling and overall navigation is very laggy. If I scroll a few pagers further it takes sometimes a a while like 1 or 2 seconds to load the page. The hardware I've tested this on was a Galaxy Tab S9 and my desktop computer with strong Hardware (Ryzen 7 5800X, 4070 and 32 GB Ram).