The changing issue with pull ups is indeed annoying and why I ended up using diapers as well. One solution I saw mentioned somewhere was to wear one pull up over another one, then when you take one off, the fresh one's still there to be used without having to remove shoes and trousers. I haven't tried it myself as I figured it would be really bulky.
My issue is pretty mild so I can get through a working day with a pull up (I use the Tena Premium Fit ones as they're 'Maxi' absorbency) and then I change into a diaper if I'm going on somewhere after work. Whilst they're less discreet, I figure it's less embarrassing if non-work friends see a glimpse of my diaper rather than work colleagues (It hasn't happened yet though!).
Another solution could be the belted products (like the Tena Flex), they're sort of like a halfway house between pull ups and diapers - basically instead of tabs there's a belt which fastens around your waist with velcro which you then attach the front of the pad. They can be unfastened and refastened as many times as you want so like pull ups, are great if you've got a mild issue. I found that the velcro tabs ended up digging into my skin though and they ride up high like regular diapers so you don't really gain anything discretion wise. I switched to taped diapers due to the skin issue and to be honest, I find that the ones with the two tape system are just as reliable in terms of being able to refasten them.
I agree that taped pull ups would be much better. It's frustrating to have to wear a diaper due to the changing issue.