i'm not sure i'd upgrade from 2.3.7 to 2.4 again - if you do, make sure you are backed up. i left part of it to my host and that was a terrible idea. make sure you turn off permalinks if you install from the admin and install directly on the server if possible. i ran into an error about 90% and had to ended up hitting install twice more. this caused database errors that i had to clean up - all solveable but it took a while to correct and support is slow given the fact that this is a new release. i still have not figured out completely how to remove redundancies with locations. does anybody know how to remove redundancies in regions? for example if i have a listing in California, and the classified lister wants to enter 'California' there are two fields that appear in auto text as 'California'.
Location stats was buggy on my last install and i'm afraid to 'calculate location stats' because thats where my troubles began on the old install. Also, i've only added one country at this point as i am concerned this may have been part of the problem.
Now that it is installed and everything is basically working like it was i'm happy, but the time it took to get here was not easy but if you are confident in your backups and ability, you should be okay.