My initial impressions with Rome 2 started delightful, then after sinking my teeth into it turned into rage. The first patch didn't do much other then make the game actually run for more people. The second was a huge step in the right direction and now I would go as far as calling three the patch that fixes the game or at least makes it playable.
Here's just a small list of things it does:
Reduced infantry run speed, charge speed and acceleration in battles. (from patch 2)
Units that charge while in formation (e.g. block formation) stop sooner on contact with the enemy, to reduce "blobbing" where units converge into a disorganised brawl.
Hit points for all units have been increased in combat.
Reduced melee weapon damage in battles, and increased melee defence from shields.
The masses of horses and men on the battlefield have been made more reasonable.
Combined battles where there is no navy in the defending alliance do not have *Victory Points/Baggage Trains
Victory Points have had their capture time increased by 3x their previous length.
Cavalry can no longer capture Victory Points in battles while mounted. They can still neutralise the Victory Points if they were previously in enemy control, and capture Victory Points when dismounted.
In Battles, the number of ranks now factor into bracing mass bonus for collision system, i.e. thin lines will make you lose your bracing bonus against cavalry charges from the front
Fixed bug with ship artillery not firing on buildings reliably in battles.
In essence it slows down combat to Shogun 2 levels and troops actually keep formation now. While this is still too arcady for my tastes things are much more reasonable now (and that's what mods are for). The campaign AI no longer seems brain dead and will actually defend itself. Still too passive for my liking but it was the same in shogun. Combat AI now seems to do a decent job or at least doesn't make utterly stupid moves anymore. Naval combat still sucks but hey at least it works now (balancing is terrible but at least mechanics work).
The game is still missing family trees and internal politics is still a joke but things actually work as intended now. Also the campaign UI has been improved. Is the game as good as Shogun 2? No. Is the armor penetration stat on weapon attack combined with the new troop HP system still a bad idea and makes ranged units OP? Yes. Is the game still missing formation controls for ranged units etc? Yes. Is the game actually fun now and not totally SimCity broken? Yes.
There is still a huge list of stuff that needs fixing but it appears the devs are actually trying. It only took them 3 weeks after launch. Pretty much all of the remaining issues can be solved by mods like usual and most of that's balancing stuff anyway. I can actually say that i'd recommend you get the game in it's current state next week when Beta 3 becomes Patch 3. It's not a marked improvement over Shogun 2 but that game was pretty much the second coming of Christ for Total War. It is however a solid iteration of Shogun 2 that while missing some features makes up for it in scope and sheer size/ variety.