I got a spray-on because things do NOT slide around on it. I've seen complaints from people that were used to sliding things in and out of their truck and could not after the spray-on.
I also feared the drop-in would wear the paint of the bed and allow rust to start - undetected because the drop-in covered it.
Check my web-site link in my signature for pictures of the truck and liner.
IMHO - I think you'd be unhappy with a spray-on.
I like mine.
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1999 F-250 XLT Super Duty Crew Cab Long Bed
V-10, Automatic 4R100, 4.30 Limited Slip.
GVW = 6700# Towing Capacity = 13,300#
4 Wheel ABS disks + Reese 15K hitch
Dark Hunter Green. Ford Running Boards.
Grey Rhino-Liner. Captain's Chairs. CD+Tape
* * * Non-Leaking Sliding Window * * *
http://members.home.net/jchartier/jnctrk.html