If you "enjoy" going up against the AI with Infantry and finding them defending with Longbows, that's fine. But it's certainly not a challenge, and I don't think it's the type of "enjoyment" that should be aimed for - if you really want that, you can World Builder some Infantry into the game. The other option is to deliberately handicap yourself so that you don't get too far ahead of the AI - in which case what's the point of playing? I shouldn't have to play poorly just to have the AI be a challenge.
Bh
Well I think you missed the sarcasm contained within the single quotes

No, I would not enjoy a situation where, every time, the game would end up with the human mopping up the AI world with howitzers on rails backed by bombers, as in (was it Civ2, 3? shoot it has been so long I can't remember!

)
As that suggests, I've been playing the Civ series since Civ 1 first came out. I don't normally post on these forums, but lurk quite a bit specifically in search of the kind of game tips, strategies, analyses and insights that experts like futurehermit or aelf offer - from the former whom I learned the basics of SE, an approach totally unknown to me, and the latter the finer points of diplomacy (aelf). I played with the full on BetterAI mod + Warlords quite a few times before the BtS release, naively thinking I was "preparing" myself for BtS (so you can imagine my surprise at the slower tech pace), and yes, that was a challenge all right - just ask futurehermit about Sisutil's first Peter ALC game, also the first (and last, I suspect) ALC played with the above

- he got his head handed back on a platter by....Ragnar, now the BtS Designated Village Idiot, after the AI Oracle-slung to Feudalism in the BCs well ahead of Sisutil. (Who, for the record, I admire as taking the time to perform an invaluable service that no one else provides, deliberately playing for the so-called "average" player, though Sisutil can have quite a few tactical tricks up his sleeve. But he shoulda listened from the get go to this guy called futurehermit).
So I've been around the block a few times with this game, and there are many paths to boredom. I hardly want the game handed to me on a silver platter (Yeah, using the metaphor again!) every time so I can once again pat myself on the back and tell myself "Oh goody! I'm King of the World, once again! Ain't I the greatest!", but consistent masochism is a bore too. Although at least Blake's Warlords BetterAI made the thrashing - I'd say I'd lose 2 of 3 at my 'normal' Monarch level - militarily interesting, so now I am thoroughly trained in watching the Power line and preparing an experienced force ahead of time. But Warlords without the full-on Blakes' got to be a bit of a one dimensional bore at Monarch and above: post-Liberalism you knew that the AIs' - almost all of them - were going to beeline to Artillery-Rocketry for Apollo and that in was inevitable that Bismarck or whoever would have built it while you were frantically huffing and puffing your way past Industrialism. Unless you strictly followed the expert advice and stuck to the beeline yourself, or made the stab for the only alternative, aelf diplo manipulation and beeline to Mass Media, etc. And a runaway AI - fuggettaboutit.
At least BtS gave the tools to deal with the runaways, for the first time: corps and espionage. It has been little discussed (in another off-topic aside), but I think that was part of the intent of the BtS design, to address the problem of the runaway, both unfun AND unchallenging (since there was nothing you could do about it). Not surprisingly, together with the overall tech pace, these need tweaking after the initial release. The whole software world (I work in it) is like that now, the community is the developer, the worms are the spice (yes, I'm disappointed that BtS didn't continue on into a Genetic Age as a standard feature

), get used to it.
So the conclusion? Yes, as said before, the overall AI tech pace needs to be kicked up a notch, even for us weenie mediocre types

I don't agree to eliminating the uneven AI development - as with some other posters here, I like that for its "realism" - and lets face it folks, it may be a game first of all, but it is a game whose particular cache' is to secondarily attempt historical simulation, and it is the epitome of Civ game design to achieve both simultaneously - so long as it doesn't make it consistently easy to win by mopping up the backwards AIs and therefore attain overwhelming geopolitical-economic leverage over the more advanced. Just advance them all a notch upwards (i.e., restore some of the original Blake Better AI teching ablility and balance that with espionage and corps).
I also don't agree that _all_ the AI's are _always_ behind me _all_ the time, and wouldn't believe it if someone playing at their usual level and configuration a sufficient number of times with _random_ leaders claimed so: certainly not with the overpowered Eliz who I put up there with the Incan as the "I always want to win" leaders of choice, so they don't count. (Note: not inferring that the player in the posted sample is one of those, no he is clearly an expert who appears to have deliberately chose Eliz to execute that gambit, but for that very reason this hardly can prove the general case being made here) That has not been my consistent experience, as others have posted as well. I certainly don't see _every_ AI with just LBs when I have Inf! A diagram may help illustrate:
BtS AI Tech Position relative to Player:
_______ <---Experts
|
| Advanced AI's <---Me
|
--------
|
| Middle of the pack
|
--------
|
| Backwards AIs
|
_______
BtS AI Tech Position relative to Player, desired adjustment (perhaps):
_______
|
| Advanced AI's <---Experts
|
-------- <---Me
|
| Middle of the pack
|
--------
|
| Backwards AIs
|
_______
But tell you what, I am going to try that Liberalism -> Rifling sling to see if I can kick butt, cuz I like to mop up the world every time, and this looks like my chance before the patch

But with _random_ leaders and climate (I always play with random climate), Monarch Large Epic as usual. And restart if I randomly get Eliz!
And did we mention the GW GSpy bomb exploit?

I've just made it a rule not to use it that way until it is patched.
So it looks like Blake has more work cut out for himself. Who knows, maybe BtS is a secret Gov't makework program. But remember, in the final analysis, it is all just a game....just a game...just a game.
So bump up the pace, if only for the gaming pleasure of reading up on more clever gambits from our esteemed expert community - absolutely no sarcasm intended here at the end.