towers have their place but if you are doing much work up there then i would get it scaffolded
even if your good with heights it is a little nerve racking on a tower - if you are standing at 4mt you are close to gutter height
towers move and the more you move the more they move - it can feel like surfing at height !
if you do decide tower then i would tie it to something secure at top
cherry pickers you get fed up of being caged in and bars in the way
scaffold is a solid safe platform
until you have stepped back onto a tower after being on a roof and felt it start moving outwards - you don't know how much you value solid ground
