I struggle to get creative when constrained to the chair and have noticed I go a lot more frequently to the whiteboard to brainstorm a problem now that I'm already standing at my desk. That doesn't mean I get better results, only that I find the office space offers more to me in general when I adopt that active stance. This is going to sound lazy, but I'm in an open office and i also find I am less resentful about having to walk out of the room to get some thinking space when I'm not having to sit down and get up again all the time.

One thing to note vis a vis long term health is that standing with good posture requires using your glutes, hamstrings and abdominal muscles. If you fully commit to a standing position and don't do some basic strength exercises in these areas you may end up tilting your pelvis forwards a lot, which makes the whole body tighten up. Ironically its people with back problems who are the most keen to adopt standing desks, but if you have a history of back problems or a diagnosed condition often the last thing you want is your whole body tightening up as this could encourage injuries. This is one reason why the general advice is not to underestimate the effort or concentration required to transition to a standing lifestyle, and to take it slowly and mindfully.