How does Rome: Total War change when playing as a non-Roman faction?

When playing Rome: Total War as a non-Roman faction, how is the game affected? In particular:

• How do the units affect strategy? For example, are non-Roman basic infantry weaker than Roman hastati?
• Is the selection of units smaller than Rome? Does it matter?
• Does the game suffer from any major gameplay issues as other factions? What about if the game is modded to allow non-playable factions (like Macedon or Rebels/Slaves) to be playable?
• Overall, is the game easier or more difficult?

One of the most important differences is that you won't be able to build Roman roads. As a result, your ability to move through your own territory will be much less than the speed of the Roman players. You will generally have two other major differences:

1. Faction units: I really like using elephants on those sissy Romans. However, I have great difficulty steering a phalanx properly. This is generally a distinction that doesn't make an overall difference in terms of the game.
2. You'll find that it's much easier to capture the Roman territories than it is for them to capture yours. You see, they build these great roads. You can sack towns all up and down the Mediterranean while they're still trying to work their way across the Alps....

I've not played in a while however I know for certain that;

1. If you play as a non-Roman faction the variety of units, buildings etc. is generally less than if you were playing as a Roman faction.
2. There are definitely some units and buildings you can only use if you play certain non-Roman factions.
3. Most non-Roman military units will be weaker than Roman units due to the technology gap and the same can be said for town/city defences however there are sure to be some specific units that have benefits and abilities that can overcome this gap if used intelligently.
4. I don't know of any gameplay 'issues' or bugs associated with playing as a non-Roman faction.
5. Finally, if you play as a non-Roman faction the end game goal is to control all the cities in the map as appose to the Roman end game goal which is to control the Roman senate.

Hope this helps

In my opinion there are 4 key concepts when playing a non-roman faction.

1. No senate missions: you dont have to please the senate with silly missions like blocking far away ports.

2. You lead the faction: as no being part of a superfaction, you can do anything you want, trying diplomacy, conquer where you want to, making migrations (interesting post on Heavengames.com).

3. Units: Some factions have a good variety of units, not so much as the romans, but it involves a different kind of strategy that you can try to do.

4. Starting position: At the begining there are different challenges like by example the Seleucids is surrounded by 5 factions, it can be very challenging, or the Britons trying to conquer europe from Britain.

Its true there you can build lesser buildings, like road upgrades, but bonus from temples are completely different and can be more useful than roman temples.