Thats very curious as the animations on the menus are quicker in 2.x than they were in 1.x and should be identical to the OS ones. Note that the desktop menu in Win11 is for some reason not animated at all.
If you create a registry value here HKEY_CURRENT_USER\SOFTWARE\Stardock\Start8\Start8.ini\Start8 called "S11_NoMenuAnimations" of type String and give it a value of "1" and then sign out and in again those animations will be disabled entirely.
In terms of changes there are a huge number of enhancements over 1.4 with 2.0. Multiple new menu styles, support for tabs, lots of new options for groups, inclusion of filtered folders as groups, new taskbar pins etc. It should also be noticeably quicker in use.