Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
Ultima can be described very simply: it is Slackware pre-configured into a very useable desktop. So, DO expect Slackware's stability, performance and simplicity, as well as low hardware requirements. DO NOT expect cutting edge technologies and latest versions of packages - Slackware, and therefore Ultima, stick to what works for them.
Installation is also pure Slackware - perhaps there were some changes 'under the hood', but to this user (who admittedly hasn't installed Slackware in a while) the installer appeared identical, apart from different set of packages available for selection.