In general, there are three approaches to suspension building/buying:
1) Just get the lift. This is typically simply a moderate quality spring that has no special design parameter other than a higher than stock spring rate and desired lift amount. It may just be springs and may be offered with a standard cheap shock ("nitro" or "hydro" shock). You will not get the benefit of a spring and shock suspension that was designed as a system specific to your vehicle.
2) A "kit". Here you get a spring and shock combination specifically designed for the vehicle. OME fits directly in this category. FOR and Slee kits also fall in this category. Part of the discussion in this category focuses on the variances between the kits based on their designs. A common mistake in this class is focusing on lift height as the primary factor.
While OME may have reasonably well designed kits, OME is not a rock crawling company and their suspensions are more designed for "overland" use. It is known in multiple markets that OME suspensions are prone to premature spring failure if purchased with the intent of a high volume of hardcore rock crawling use.
You might also imply that a suspension designed for rock crawling might not be the best for high speed overland use, although usage bias could be seen as a venn diagram where you want the heart of your bias to fit well with the design premise of the suspension, leaving the "exceptions" to low volume use. When you look at suspensions that cost more than OME, what you may be getting is a broader "sweet spot" in cross functional use, because the suspension was designed specifically to accomplish that using more costly components.
The point is that a system will produce what it was designed to produce, and understanding the design intention is a lot more important than labels like "extreme, competition, expedition, etc".
Generally speaking, kits are more expensive than the budget lift, and if you are new to the sport and/or vehicle and want to assess a lift before settling in on a long term approach, going with Category 1 over Category 2 may make sense. You might say "an OME 2.5" lift is better than a Skyjacker 2.5" lift", and it probably is in the sense of one being a "kit" and the other just being a "lift", but neither may be what you need from a design perspective.
3) The "Kit Plus". Here you are typically taking the spring you want and working shock travel around that spring both for performance and tire fitment. A "kit" may do this for you for a target range of performance, but if you find that you are spending excess time in the "exceptions" usage, you might want to tweak it or have custom springs designed as well as making suspension linkage modifications.
People who play in this 3rd category typically live in a world of severely diminishing returns because it is difficult to take any "dual purpose" vehicle well beyond it's original design premise without radical modifications such as body/frame cutting. However, you can take a standard spring like a Slee 6" and effectively design a radically different suspension than the Slee 6" kit.
In my opinion, this forum is continuing to struggle with the embedded mix of ideas in the first and second categories when they are very distinct approaches. None of these suspensions are automatically the best. I personally think OME is an absolute waste of money independent of resale value for somebody who is dedicated to rock crawling on 35's (or bigger) - you can only look at it as value if you don't assign value to your time and spring longevity.
I think OME is an excellent value for the "camping plus" set who may crawl from time to time, and that Skyjacker/Downey are perfectly fine for trial lift evaluations for the budget minded who are trying to get a feel for their needs.
And I think you go FOR/Slee for kits specifically designed for 35" tires if that is your goal, choosing between them based on your usage. They have very different underlying designs and accordingly different outputs.
It is best to first pick your category between 1 and 3. Once you have settled on a category, then look to the design premise (and cost) of each so you make the right choice for your usage. It doesn't matter how "good" a kit is if that kit was not designed to support your usage bias.