The two main reasons are Map sizes and Unit control.
My playing style is very expansionist and hoarding based, its why I dont play online, I prefer more realistic strategy as opposed to rush.
Im not getting into the rush debate so what little I say here about it is all im going to say, its not realistic and I dont like it, thats the only reason I need. Did alexander the great send 7 horsemen to kill some indian villagers and stop their economy so he could have an adavntage? No, clearly not. For me it removes the fun of building an empire and is a poor substitute for good strategy and competant military tactics.
That being said, I like to enjoy the game, build my cities, level up my techs, build walls, build towers, build forts and amass resources until such time as I feel I am ready to implement a war campaign with great effect and the economy to support it.
Here lies the problem. Age 3 is distinctly limited in fun for my kind of game. The maps are tiny and by the time I expand a little I am camped right next to his walls, esentially meaning we start fighting before the first age and never stop...its boring, he throws himself at my walls and by the time I am actaully ready to fight he has crippled his economy throwing 10k units at my walls for three ages.
I like space and time to enjoy and build before EVENTUALLY bumping into a civilisation and getting down to the war. In a map so small, I can only bear to play 1 on 1 and even then its cramped and forced early combat from the get go.
On top of this being an expansionist im also very big on defensive construction. I build walls, and firetraps, and killingrounds and set up mainstay defenses. Sadly in AGE3 the removel of all the unit control and formations makes this just tedious. Why do I have to micro manage every detail of a defensive rig?
I should be able to organise the formations and positions and leave them to defend, if theres a flank problem or a break I have floating cavalry and infantry to throw out to boost a defense, for the most part though my cannons, muskets, archers and grendiers should be able to be placed in formations where I want them and instructed to hold ground and fire at will.
The guard command just serves to clump them all together for easy killing by enemy cannons and without it they go wandering off like idiots.
I still win the battles but it awlays boils down to dragety clickety dragety clickty warfare with no structure or organisation and all my defensive planning goes to waste. Ohhh for the control of Total War where my lines hold fast and do what they are told to do!!
I have downloaded all the large maps I could find (ONLY three), and have the larger maps from the patch, but having now played them all to death, im just lacking the will to play another map.
In AOE2 the random maps were excellent, you always got something different and the size was huge. I could adavnce the ages and build my great walls and by the time I met the enemy in battle it was the right time and the battles were worth having.
With the unit control and formations my defensive tactics looked great and worked great, I actaully felt in control and had time to observe and wait to see what was happening while letting my lines handle the defense.
Theres a lot good about age 3, the card system and home cities, the graphics are lovely, stability is great, sounds are great, the techs are interesting and the era is great fun. The natives are a great twist and the trading posts add a new tactic to the game.
The small maps severaly limit tactical options for combat. No more sneaking units round the back and waiting until your enemy had his main forces marching across the map to attack before springing a swift suicide mission into his agriculture and financial setup in his home base. A quick body strike to weaken his build times and soften him up for the frontal assualt.
Or,laying ambush troops in the middle of the map and ambushing his armies in transit to attack you before he can deploy an effective defence.
The game for me just boils down to him throwing mass upon mass of horses and pikemen or halberdiers against my walls and cannons, while I sit dealing with the tediom of reppelling him until he runs out of resources and has to slow down.
I still get to build up my economy but by the time I am ready the opponant has so critically weakened itself by wasting units on my defences, I can wipe him from the map in a single attack because he neglected economics for repeated rush warfare.
Its just dull. I know the game will suit rush players, and I have no objection to that, eash to their own, but for players like me who prefer a longer more developed and tactical game its quite repetative and lacks much that the previous game did so well.