I’m a scientist, not a developer. First of all, many thanks to all contributors for your great work. JabRef is one of my main instruments raising performance to new levels. JabRef 5.0 feels much better than predecessor. Below are few issues which are not critical.
JabRef 5.0–2020-03-06–2e6f433, Windows 10 10.0 amd64, Java 13.0.2.
Laptop: Intel i5-5300U, 8GB RAM, 128 GB SSD
System: Windows 10 Pro (10.0.18363), Java 8 (1.8.0_251-b08)
All relevant software is up-to-date (issues were noticed before and after update).
Significant lags when typing in the search field, even in the case of few hundreds entries in the .bib file. Simple solution: introduce an option to disable the mode “search/filter-as-you-type”.
Significant (a couple of seconds) delays when switching between tabs. I think it is common to actively work with multiple bibliographies and often switch between tabs. Use case: while working with a new paper, copy entries from an old paper / from co-authors’ bibliographies. Simple solution: if it is faster to switch between windows rather than tabs, then allow multiple windows of JabRef (at the moment, opening JabRef sets focus to the existing window).
Buttons mentioned in Docs (At the right of the search text field, several buttons allow for selecting some settings) are actually located in a different place (see the image). Frankly, having buttons as described, always visible, would be mode convenient and seems more intuitive. At lease, please update docs.