There's definitely a difference between an 80% solution and the full 100% solution providing the fully rounded experience. Will the market leader 80% features be included as an upgrade for free or available as a value-add for a one time or monthly fee?

Others have mentioned checking the track record of said company to see how often they follow through on new features, but also their general development pipeline to know how long you have to respond if they develop and release on a similar schedule after announcing, such as it taking 2-3 quarters to fully implement vs longer.