First up, spacer kits. Spacer leveling kits are nothing new, and are a trusty and popular way to get some extra front ride height out of your truck. Spacer kits add some extra front lift without too many hassles or fuss and usually keep your truck's street ride near stock. They're also extraordinarily inexpensive, with most kits costing several times less than a full leveling shock/spring assembly or coilover kit. They do, however, have a couple of issues. The biggest problem with spacer kits is that they aren't a performance improvement. Spacers "only" add front height. They don't improve rebound, response, articulation, or ride quality in any way. The other issue that's common with spacers is bouncy turning, some extra NVH (especially with metal spacer kits), and that a few kits require cutting your truck's factory studs. Basically, spacers are a goo choice if you're on a budget and aren't really going to be yanking your F150 around too hard on the street or off of pavement.
So now we come to leveling shock assemblies and coilovers. These kits are our preferred method of raising front ride height due to the fact that you usually get improved suspension performance out of strut and spring or coilover leveling kit, unlike typical spacers. Most loaded shock/spring kits and coilovers are extremely easy to install and drop right in place of your factory hardware. Coilover kits are especially powerful and are basically the "go-to" systems for getting improved off-road performance. These kits also give you plenty of ways to further improve your truck, allowing you to save up for improved rear shocks, UCAs, rear blocks, or other hardware to get even better performance. Still, these systems have a few drawbacks. Principle of which is their cost. Even the most basic shock/spring leveling kit is double the price of the simplest spacer kits, and more capable hardware can clear out your piggy bank very quickly. While we say generally that coilover kits improve performance, their abilities can vary from one extreme to another from brand to brand and type to type. It's extremely important that you do your research and find the system that meets your needs. The last issue is really only for really powerful off-road coilover kits, but it's not uncommon for those systems to stiffen up the street ride of your truck. I wouldn't call it "bad," but there's a noticeable difference. It's like being in a car with a basic lowering spring kit. I like it, personally, but if you're expecting a baby smooth ride, you're not going to be very happy.