Here's a utility that tremendously simplifies the application of various patches/upgrades to all of GOG's Ultima releases:

http://www.pix.oneuk.com/UltimaPatcher.rar

Some notes from the creator, Pix, here:

http://originadventures.wordpress.com/2011/09/08/ultima-patcher-update/

Is there an option in-game in XU4 to switch to the VGA graphics set with the u4upgrad? If there is I couldn't find it, and had to edit the program's cfg file.

From the main menu go to Configure (C), Video Options (V), Game Graphics Options (G), then select the graphics mode you want (it includes several different modes).

I love the custom music they put in. :)

awesome, thanks, there are so many tileset options, "New" is really nice =D

I recently purchased Ultima 4 off ebay (yay!) and am using XU4. Since I never played the game before, this version allows me to enjoy it in 2012. The original game, the spellbook, the manual plus the slightly updated graphics make it a great experience. Each time I purchase an old game on ebay I end up telling my friends how they used to include great stuff in the box, like books, stories in manuals, maps etc. They really add to the experience. *sigh*

I just finished U4 using xu4 last night and it was great. The improvements to movement, command delays and reagent mixing made the game play much smoother.

However, I ran into one xu4 related snag during my quest for avatarhood so I figured I'd post it here to hopefully help others avoid the frustration.

xu4 has it's own save files for your progress. The common locations are listed at the bottom of this faq: http://xu4.sourceforge.net/faq.html

The reason I bring this up is that when I got to the 8th floor of Wrong the game kept freezing on me. After trying different things and looking online I finally circumvented the issue by copying my xu4 save files into the GOG U4 folder. I then ran the GOG U4 launcher, grabbed the stone, moved to the next dungeon, saved, and finally copied these more current save files over the xu4 ones. I had no issues completing the game using xu4 after that.

If that's at all confusing I'll try to elaborate more. Hope it helps at least one person avoid a headache.