Board Thread:General Discussion/@comment-24111700-20141030185332/@comment-1352718-20141030190440

Upgrade increases their abilities (those affected) beyond their original intended use. Though I'm sure that Ultimates are superior because "Upgrading" an Alien requires the use of two Omnitrix users. Though clearly, it's a nice substitute from Ultimates.

Now if we were talking about Ultimates + Upgrade, Upgraded Ultimate Echo Echo would demolish everyone.