One thing that always struck me about FS2, aside from awesomeness of course, was how sluggish even the fastest fighters sometimes seem. 150 m/s translates to what, 500 or so kilometers per hour? In your typical flight combat sim, arcade or otherwise, even slower aircraft easily break 700.
Before I begin, I will say that I understand why its a good idea for FreeSpace 2 (as it originally stands) to have comparitively slow fighters. When fighters with high speed are combined with high mobility, acceleration, and an AI that enjoys randomly messing around with all these variables to try and avoid getting hit, you find that it is a complete pain in the butt to actually hit fighter-sized things if they don't want you to hit them. But considering some of the things the FS2 Open project makes possible, it should in theory be possible to negate this problem via one of a few methods.
1. Automated aim. If you have played the Wings of Dawn campaign, the "Promethius Frame" had this applied to its blasters (they automatically aimed at the enemy's reticle, but don't alter their course after being fired). Suffice to say, this particular craft had a rather large "auto-aim zone," and to remain a challenge you would probably want to limit it to, say, the very middle 10% of the screen.
2. Slightly spreading overly powerful and rapid-firing guns. That is to say, like those in Ace Combat or other modern flight sims. If you have played them, you know how few bullets it actually takes to tear apart an enemy aircraft. Putting a similar system in effect for fighter weapons here would allow higher speeds to be viable here to some extent as well. This of course has problems though, as FS2 AI tends to be pretty good at aiming where it needs to in order to hit something, so AI will generally tear apart players too easily unless they are modified to be at least slightly "bad at aiming" their primary weapons. Some balancing would need to be done with capital ship health and weaponry power too.
3. Slower turn and acceleration speeds for the now-faster fighters. If your turn rate is decreased, and you can't speed up or slow down as quickly as before, then you will be easier to hit. Likewise, it is easier to aim your own fighter's guns at the enemy if both of you are turning more slowly. Honestly, the fastest turning FS2 fighters turn at speeds over twice that of even the fastest turning modern fighters.
Anyway, just some thoughts on the matter. It wouldn't necessarily be a purely cosmetic change either, but could allow for new tactics to become viable in combat (for instance, actually strafing capital ships with fly-bys instead of just standing back and "sniping" them, or dashing in, launching torpedoes/missiles, doing a 180 and getting away from their guns). One thing I notice is how close-strafing runs against capital ships, with all their new beauty and potentially cinematic "trench run" moments given to them by all our model designers, are really not a very smart thing to do in Freespace because fighters are so slow that the ship's defensive turrets will pound away at you the entire time.
I am not saying that Freespace should become Ace Combat or something (though I would like to see someone figure out how to allow you to aspect-lock 4 enemies at once sometime), but it would be interesting to try working with high speed concepts after all the time we have spent perfecting the use of the original FS2 style of gameplay, and FS2 Open has the capability to do so without making it a total pain like it would be with the original FS2 engine. Plus, we would likely hear far fewer complaints about overly long node runs in missions if we had fighters capable of 400m/s (on that note, capital ships could be allowed to move at 50-200 m/s themselves, opening up the possibility of blitzkrieg/breakthrough tactics and missions, and simply being able to have player-controlled capital ships that can be fun to maneuver around).
