Limiting the discussion to one ounce Foster type slugs, there are several, (nominal), velocity levels available: 1200 fps, 1350 fps, 1600 fps and *1700fps. Realize those velocities are usually taken from factory 30" test barrels, so shorter slug gun barrels will register lower actual velocities.
Most of the "tactical" rifled slug loads are rated at 1200 fps. Federal's Deep Penetrator at 1350 fps and then 1600 fps for most of the one ounce "standard" slugs.
With the same payload, the
usual relative POI will run somewhat higher with lower velocity slugs due to increased barrel time. There is, however, a
marked reduction in perceived recoil when dropping down to the 1350 fps level.
The Federal Deep Penetrator, (1350 fps nominal velocity), is my prefered among the readily available Foster slugs. The slightly harder alloy with a thicker nose and sidewalls result much deeper penetration - needed for larger hogs. And with a projectile starting at .73", how much expansion do you really need?
On recoil, simply draping your soft shotgun case over your shoulder will make a difference. Also, shooting from a standing bench, (modified short ladder with sandbags), makes a big difference!
On the subject of Rifled Slug Penetration vs Expansion, I found the following videos illustrate the difference quite well.
WW 1 ounce 2.75" slug
https://www.youtube.com/watch?v=FKge3FF0Hx4&t=21s
Federal Deep Penetrator 1 ounce 2.75" slug
https://www.youtube.com/watch?v=zAq5jNBrRbw&t=134s
*Remington one ounce 3 inch slug load.