I believe I have played Travian precisely once -- in other words, I created an account, placed a few buildings, realized it was exactly like Tribal Wars and never bothered with it again.
I played Tribal Wars for 6 months or so, until I realized it was all futile to try to go on in that game because, as someone pointed out, I did not join the server I was playing on from day one.
On top of that, Tribal Wars had a two-tiered approach to the game, which meant that subscribers could have an unlimited building queue , whereas non-subscribers were limited to two buildings at a time. At first it did not mean much, but over a longer period of time, I'm pretty sure it gave a strong advantage to subscribers.
But what really led me to think it was a waste of time was when I compared my own statistics to those of another player who had started at roughly the same time. The difference was that I took over small abandoned villages in my immediate vicinity and developed them into strongholds to consolidate my position, while rarely attacking other players unless attacked first; he, on the other hand invaded the large villages of other players. Worse still, he had a pattern of joining tribes, staying a few weeks with them, growing fat on invading their inactives, then leaving and joining an even larger tribe, all the while invading the convenient villages of ex-tribemates. Last time I checked, he had changed tribes at least 5 times, yet there never seemed to be a shortage of larger tribes ready to invite him along. Result? After half a year, he was quadruple my own size.
Likewise, wars were just started over peccadilloes (such as harbouring refugees), hearsay, personal disputes, and sometimes just the whim of their leaders despite having an alliance with the tribe to be attacked (think Hitler's "let's invade Russia today, we'll be done with it before winter"). You'd wake up one morning and discover that you were under attack from 40 different places at once. A day or two is fun in a challenging sort of way, but when it extends into a week, it quickly becomes more bothersome than it will ever be worth.
Then there were the question of tribe sizes. Small was impossible; remaining so was just asking to be invaded. So I was forced to graduate from a small tribe of four players, to one of maybe twenty, to one of over a hundred with two sister tribes of similar sizes. The tribe of twenty was okay, but the logic that the tribe of a hundred+ members used to convince us to join them could be summarized as follows: "your area is vital to us, so if you don't join, we'll invade you." So you had to merge into larger tribes or risk being invaded by them. On the World I was playing, one tribe was notorious for controlling an entire quadrant, and for only welcoming insanely large players to join them. They were also notorious for bullying smaller players/tribes into giving them villages. If you refused, they invaded you; if you gave in, they would be back anyway...
Large guilds have never interested me in any game, especially if they are just transplants from other games with the same leadership always in place. So I prefer smaller guilds, and I tend to choose my games accordingly. I have two criteria, essentially: First, that a small guild can play most of the aspects of the game without being eaten alive within a few days; second, that a defensive style of play is also viable. Neither of these seem viable in Tribal Wars, Travian, Ikariam or all their clones. (Hell, I remember it was not even an option in that old Utopia game; in one case, upon remarking that defensive units of one race had a defensive bonus and therefore gave you a stronger defense, I was answered that the purpose was for you to retain less defensive troops at home while you're attacking others. What ruined that game, however, could be resumed in one word: Absalom.)
It would seem that such games only maintain an impression of movement by just launching more servers as the old ones stagnate, a luxury which most genuine MMO's don't have. Tribal Wars, for instance, was maybe at World 10 when I joined a year ago, and World 13 last winter; now it's up to World 24... With such an expansion, maybe even Shadowbane could have looked competitive...