Depends
That all depends on how much planning you do ahead of time.
If you dont mind laying on your back, and working up in a dark recess, while reaching up, then I would guess access could be classified as high as "crummy".
If you plan on making things accessible, put in wiring that is long enough to include a service loop, and so forth, it wont be too bad. You will need to remove the panel though-------here is where a multi piece unit shines.
I have run all of my wiring along the lower angle piece that the panel face mounts on. Each wire is 5-6" longer than it needs to be, so I can un screw the panel pieces, pull them out a couple of inches, and then lay down flat. I am making up a few brackets that will mount to the bottom bar, and hold the panel in the horizontal position while I work on it. Having a 3 piece panel is a big plus here.
No, it isnt done yet, when it is I will post photos to show the panel in the "service" position.
This is the next best thing I could come up with compared to a hinged at the bottom, tilt out setup, which wont work due to the side longerons, and the depth of instruments mounted at the top of the panel.
