State Troops of the Empire
There are some new changes to how the state troops work, but in overall i think the change of the swordsmen have made the halberdiers the best choice for a regimental units and i will explain try to explain why. Before the new book my choice was the swordsmen, they had 4 in WS and I they also had 5+ save with parry for the same price as a halberdier or spearmens, and they hold their ground a lot longer then the other units.
In the new book they cost 7p/model and are back to three in initiative, they still have four in weapon skill. But with the hatred boost and prayers from the warrior priest they just don't do the damage you are looking for. On the other hand the halberdiers cost 6p/model and will do some more damage with the re-rolls from the priests. In my opinion they are the new Flagallants for this army (with the proper boost ofc). I see a big unit of halberdiers as a standing unit in every Empire list, maybe 40 with a detachment of 20 free company.
Still i cant really see the spearmens as a solid unit, maybe in a gunline list (if there is anything like the old gunlines alive in this book)
The Handgunners and X-bowmen are still at BS 3 so they wont even hit the barn in the middle of the battlefield. Most shoots in 8th ed will be at long range so at best they will hit on 5+. The new book clearly goes away from a shooting army to a close combat army or more diverse army. it might be possible to have a bit of the best from both worlds including magic.