Well, so far a few games have been had between myself and Sinistar. Still worth a try though, even if you ignore the campaign because there are few things it does differently than UO (there faction called Administratorium that UO doesn't have - apparently, you are a planetary governor, throwing waves of PDF and obsolete vehicles at your enemies, with the option to align yourself to various outer powers like Chaos, Tau, Space marines) But when you are playing campaign mode, having nearly every attack or defense turn into an hour(s) long slugfest, it can exhaust you pretty quickly. In practice that means, unless you immediately rush your opponent and even then hope for the best, nearly every match will boil down to a gruesome, bloody siege warfare. The problem I have with TW in campaign mode is that while there are super units and even lots of normal units get damage upgrades, the HP of structure is also considerably higher.
Why this is relevant to your question is the fact TW's game changes also apply to campaigns (you can get a version for Dark Crusade easily, Soulstorm one is a bit trickier due to some dispute on ModDB). It adds lots of new units and even factions, though the scale of battles is a bit smaller than UO - for instance, UO lets you build multiple types of titans, where TW only has one per each side (if I am not mistaken). There is a mod called Titanium Wars which is a bit like UO.
