thay are a totally different product.....all spray-ins are a 2 part mixture with about a 10 second cure time(they mix in the tip of the gun.They are much more durable and hold up longer.....the only experience I have with a roll on is in the interior of Land Cruiser and it held up good.The biggest thing is prep with either.....wash it extremely well and let full dry(use compressed air to get all water out in cracks..... sand wherever you want it(small 4 inch air or elec orbital works great)...make sure you get everything....then wipe with denatured alcohol.....it dries fast and no residue

i had use herculiner and plasti-kote in my '72 truck.they are way cheaper,maybe $70 for a gallon but like ron86toy said they are a different product.something i learn the hard way is that most people ,like me,think the spray on bedliner will prevent rust.to this day i dont know of a product that will prevent rust,$70 or $600 ,if you have a tiny rust spot or the bedliner has chipped you are in trouble.
i would only use a good quality spray liner in a brand new truck or one that the bed is like new.
i have seen beds that rust from the bottom and still the bedliner holds like a soft mat on the top.

I have a line-x liner that I had installed when I bought my truck. I love it. the only draw back is sweeping out the bed, it catches all sorts of junk from the pine trees its parked under. it is plastic like, but durable as all heck. I went this route versus rhino because rhino looked even harder to try to sweep junk out of the back. I paid about 550$ for the liner and the side and tailgate diamond plate caps and install at the same time.

You need to sand away all rust, and then spay it with a sealer or some sort before any topcoating. A chromate primer of some sort like a zinc-chromate, or a two-part epoxy primer. I used to cheat and use a cheap Sherwin-Williams product called Jet-Seal. It was a non-sanding sealer, cheap and easy to use -- not sure if they still make it. If yo have bad pitting and can't get all the rust out, find a product called Rust-Mort. It is a conversion coating that reacts chemically with the ferrous oxide (rust) and converts it to a primer-like material. You can sand it and paint (or whatever) right over it. It's not a good idea to spray regular lacquer prime over bare metal. You need to chemically etch the bare metal with a product such as those mentioned above in order to bond to bare metal. I know that people have probably used regular primer over bare metal with good results, but that's the exception not the rule. Lacquer primer is like a sponge. It attracts and holds moisture and if this happens before it is top-coated, you can bet that you WILL have rust coming through in the future. Plus you have a real good chance of peeling later.

But then, I've been out of automotive refinishing for fifteen years and there's been plenty of changes in that time. No telling what kind of new paint technology is out there now.

Just my .02

What Norton said x2 about bare metal prep.....earlier when I said sand everywhere....I meant scuff the surface to get a good bond to the paint just to clarify.

I've been on here reading about this generation of Power Stroke because we're looking into possibly getting one for our business.

I had a Chevy with Line-X, sold it and then my fiancee had a Dodge with Rhino Liner...

Line-X is far surperior to Rhino Liner if you need something rugged. My first truck had Line-X. We had to get 2 loads of crushed gravel. I shoveled it all out, sprayed out the bed and it still looked brand new. Second truck we had Rhino. We did the same exact 2 loads of crushed gravel and I shoveled it out. The shovel penetrated the soft Rhino liner and I saw bare metal scrapes and gouges all over the bed. We brought the truck to Rhino and I explained what happened. They said they'd respray it, but I told them to remove it and I wanted a refund because I was so unimpressed. I had to take a screw driver and show them how easy it was to scrape their product off. I called Line-X and had the bed sprayed. I will NEVER buy Rhino liner again nor will I recommend it to someone.

Line-X bonds to your bed and actually gives your bed more structural integrity. I had the entire interior part of my '89 Jeep YJ tub sprayed with Line-X. I've been 100% satisfied with Line-X and so has the rest of my family.

Jason

Another good reason not to use lacquer primer -- if the topcoat (bedliner) is a two part product that means one of the parts is a catalyst (hardener). A catalyzed product will lift lacquer primer almost as soon as it touches it.

Line-X rules.
I love mine. Had to use the lifetime free warranty when a towmotor operator hooked a fork on the edge of the bed and tore the liner. I saw it stretch far and it snapped just as I yelled to stop.
Fixed it free. I saw where the damage was. I know exactly where it is in the bed, but you can't see it or any traces of it.
Fixed it the day after I called - no complaints
It is holding up well and I like the low-slip characterisitics. It sweeps out easy enough for me and a quick hit with the pressure washer makes it look like it was just installed.