When I switch between Modes (Assembly, Part, Drawing, etc.), a different set of icons is displayed for each mode. Quite right too! However, many of these icons are common to all Modes - Datum Planes on/off, for example. What causes me some concern is that the common icons do not appear in the same place in all the Modes.
For example, in my incompetence/impatience, I will frequently switch from a Part window to the Assembly it is used in and only then remember that I have all the Datum Planes Shown. this makes the Assembly slow to appear and difficult to work with. I therefore do a 'Panic Press' of the Datum Planes display icon, only to find that, as part of the Mode change, the icons have shifted; when my Assembly appears, it not only has all the Datum Planes Shown, it also has all the Datum Axes Shown. All the icons moved one step to the left during the Mode change. The other common problem is with the 'Switch Dims' icon. I use this quite a lot in all 3 Modes (that reminds me of the Bar in the movie 'Blues Brothers', where they had 'Both kinds of music: Country AND Western!'). Sadly, the icon appears in a totally different place in each Mode.
The software should figure out which icons are common across Modes and fix their positions to be the same in all modes. The variable icons can be fitted in wherever it is convenient.
This is a general observation about User Interfaces, I suppose. An icon that is always there should always be in the same place.
I do not have experience of Creo or WF5 (nor am I likely to for some considerable time yet), but I anticipate the scenario still applies.