I love having the rear ladder on mine. But then again I'm acrophobic so having an attached ladder is the only way I'd get on the roof. If I had to lean an extension ladder on the trailer I'd have never made it up there.
Slide toppers are a bit of a hot topic. Some love em, some don't. It'll be whatever you decide. In my case, I don't have them, but with the rear ladder, it's easy for me to get up there and sweep it off when I'm closing up.
There's no use crying over spilled milk, unless it's on your keyboard.