Adding Horford (and to a much lesser extent Green) will give us a variety of lineups both big and small that have solid-to-good 3 point shooting at every position, and 3 excellent/elite defenders on the floor at the same time.
KO/Horford/Crowder/AB/IT
Horford/Crowder/Green/AB/IT
Horford/JJ/Crowder/AB/IT
Etc.
That's what excites me most about this team, as it brings us a lot closer to the current NBA blueprint for success.
I think focus on our regular season record improving is also a bit misguided. This is an addition that makes us a more dangerous playoff team, for the above reason. We were simply outclassed offensively the last couple years, once we hit the postseason.