I'm a little concerned over the idea of letting the Borg gain tech by defeating enemy vessels. While I fully appreciate the realism of "assimilating" technology, as they do in the series, I find myself worried that they would be able to advance too rapidly compared to everyone else.
If you think that to begin with they have vessels with a strength of 4 while everyone else doesn't have even Warp 5 ships you can see that for a long stretch their Cubes are going to be unstoppable. Granted this is how they should be, but consider that if everytime they win in combat (which will be 95%, if not higher, of the time) and that each victory brings a possibility of a tech (in addition to conquering systems) then they will quickly become irressistable. Since the techs gained are random and not tied to the civ's vessel they could easily advance through the "light" vessels until they have strengths of 16+ before most civs have Light I's!!
The Borg ARE supposed to be superior with Transwarp conduits allowing them to reach all corners of the Galaxy in hours and vessels which could wipe out a fleet of 40 odd starships, but remember that the creators of Star Trek got round this problem by ensuring that they only appeared in a few episodes and when they did that they only ever attacked with ONE Cube!!! (So much for Guinan stating that "When they come, they're gonna come in force. They don't do anything piecemeal.")
In fact the first time that we see multiple Cubes approaching the Federation, when 15 approach Voyager, in "Scorpion", they passby and ignore it!
Naturally in Civ they don't just have one Cube!
It's an extremely difficult balancing act between making them powerful and yet not letting them go bananas and wipe everyone out everytime they're in the game.
Solution?
I can't think of one. I usually play without them, unless I play as them! However, sometimes I simply use the Worldbuilder and create a system for them surrounded by Nebula so they cannot be reached (except by the advanced probe) nor they enter "normal space". Then when the civs are advanced I place a few Cubes at random in the Galaxy and see what happens...
On the subject of Technology though, I find that even playing "Marathon" that I usually have all techs within 600-700 turns (Even earlier when playing the Borg) yet on normal Civ even by turn 1000 I still haven't got close to the end of the tech tree, usually being at beginnings of flight / tanks stage.
Would adding more technology, in line with the numbers of techs in normal civ, be considered perhaps? Of course this would mean adding more buildings / military units...
Marla x