Whenever I play a 4x, I always rush research. [b]Always[/b]. With a high enough research advantage, especially if you set all the research options to super-slow so your research goes comparatively that much faster than everybody else's, you can tech your way out of everything. "You have 20 units of Legionnaires on my doorstep? That's nice. I just quick-built five musketmen and a unit of cannon artillery. Enjoy your own ass, due to be served up on a silver patter in about five seconds." This also lets you buy your way into the good graces of just about anyone, by doling out techs to them which they desperately want, but which you don't care about because it's shit you had centuries ago and don't care about. So, assuming that they aren't outright grifting (which they probably are,) then I would expect them to be giving transhumanity [b]very[/b] incremental upgrades. Nothing that would be a game-changer, except in the intra-transhuman politics. Something that the Argonauts or the hypercorps might be working on but are still having problems with, that can make a difference locally, but not for transhumanity as a whole. For instance, suppose Omnicor, the energy giant, is meddling in things the Factors say they Ought Not Be Meddling In. So the Factors trade Starware some energy tech that's half a decade out for Omnicor's best scientists, letting Starware make a break-in to the energy sector and degrading Omnicor's position.

Another thing about the Factors is that even if they're not exhibiting technological superiority, parallel but separate technological development may still be valuable. Imagine what would happen if someone presented an alternative model for fusion or a new form of spacecraft propulsion that isn't necessarily superior, but has its own benefits and limitations.

I kinda liked root's take on the Factors as being a TITAN distraction. ( http://eclipsephase.com/mesh-archive-religion ). They haven't been a factor, no pun intended, in any of my games thus far, though, so I've not put too much effort into defining them beyond that. If that's how it goes in your game, however, the reason we haven't seen much Factor tech is because those in the know do their damnedest to cover it up. It's also very possible that a more benign take on Factors is, put simply, scared shitless of humanity, and is thus playing understandably hard to get with their technological advancements.

Convincingly alien...well, aliens are damn hard to write as a human. Though thinking on it, the Factors seem to prefer acting in smaller, contained ways (almost like a science experiment), so it might be both easier to handle and more in-character to use them in a small-scale campaign. Maybe they appear in response a flagging, failing outer system colony's distress calls and fix things up with working but heavily obscured tech, in exchange for X, Y, and Z unsettlingly oddball requests. It's a good situation to be the one with leverage in isolation, since it neatly contains your own involvement.

In my EP, the Factors aren't grifters or frauds - their trades are pretty much what it says on the tin. They are, however, significantly more advanced than they appear, as Factor communities are natural seed intelligences - trading with humanity is very much a "Buying Manhattan for Beads" situation. The threat isn't so much the Factors as the Thing that's following them. They don't want Transhuamnity using the Pandora gates because if a team runs across It, then It may learn where the Factors are before they're ready. Think "This Island Earth", with Transhumanity being set up to be Meatshields. Back on topic, a lot of the tech the Factors give are really useful, but very underwhelming; better material analysis algorithms and so forth. Advanced technology is more along the lines of methods to catalyze reactions; how to make Nucleosynthesis occur at low energies for example. Another example is protein designs, especially those containing unusual components such as heavy metals or transuranic elements.