The 'Tactical' version was made up by agency request. It does not display the 'Turret Solution' as a separate field, in theory to avoid confusion when there is a scope correction factor input. The buttons at the bottom are now vertical, so more text is displayed. The engine is the same I'm not sure what the current version is, and as I recall Delta V has some additional features that did not get added to Tactical, like loophole calcs.
Personally, I'd upgrade to Delta V, but not because it has better solutions.