Weight, if you want to take it on and off.
And for leaks. I had a Century Cap on my 94 F250. Fix one leak and two more pop up. It had lots of little windows.
Bought an aluminum A.R.E. for it, really liked it, but it was short. Cab height, the Century was a little taller.
Although if I bought one for my F250 now it would be a fiberglass A.R.E. with the door on the door.
https://www.4are.com/product/walkin/
Dane
1986 F250HD SC XLT Lariat 4x4 460 C6-Sold
1992 Bronco XLT 4x4 351W E4OD
1998 GMC Sierra SLE K1500 350 4L60E
Arizona