Well I for one am a relatively recent convert from Starfire to Starmada. As late as mid-2005 we ran a 4th Generation starfire campaign but finally grew disenchanted with the direction Starfire was taking. We needed a simpiler strategic system and opted for VBAM. We wanted a different tactical system and are now playing Starmada. The All or nothing approach of Starfire wouldn't translate well to Starmada (in my opinion).
In Starfire, once you comit to battle, you win or lose 100%. If you are in a bad spot it is almost impossible to disengage. Plus in a campaign all of the battles were variations on a warp point assault/defense and it just became a game of throwing resources down one or two warp lines. Very little tactical maneuvers could alter that. In Starmada I can engage the Hyperdrive and I'm gone. Now it is more like naval combat in that to get the enemy to fight, I have to threaten something he doesn't want to lose. So far I prefer Statmada.
While I miss the detailed back story that came with Starfire, there is quite a bit of background to run very diverse campaigns using the VBAM/Starmada combo.