fun is whats most important. I dont find CTHG or MERC to be fun. I dont care for overly abstract rules or number crunching. to each their own.
I don't use it all the time, either.
I think the key is for the players to have an investment in the fight. They need to be pulling for one side to win--instead of not-caring at all who wins.
For example, in the fight I described, the players had ties with Tukera. Sternmetal turned up with a fleet around Aramanx (story point--pre-ordained and not diced) as a show of force--to let Tukera know that they're there to stay.
The players knew about the problems between the two mega-corps, and I'm sure they expected to get into some gun combat with Sternmetal bad guys at some point. When they exited jump at Aramanx, it was a huge surprise for them to see the Sternmetal fleet.
See, they were invested in the game--in the story. They had an uneasy alliance with Tukera, but it was their alliance.
As the player's ship approached the Aramanx High Port, scanners showed multiple jump signatures. It was the Tukera fleet jumping into the system.
Well, this put a lot of tension in the game. If there was going to be a space fight, they probably wanted to get out of there. The players wanted to jump right there and then, but they needed to refuel.
So, they made dock at the High Port, set up services for the ship, and went to the bar--where the announcement was made about the emergency conditions.
If Tukera won, it would mean a lot more work for the PCs. The Sternmetal fleet would be gone, and Tukera would press to root the megacorp tentacles off the world. This is the type of thing the players had been higher to do for Tukera in the past (Tukera playing dirty).
But, if Tukera lost the fight, the campaign might take an entire different direction--they'd have no fighting ships left in the subsector.
So, the fight between Tukera and Sternmetal was quite dramatic.
I let the players play the Tukera ships, while I played Sternmetal.
Every third round, we'd play a High Guard combat round, followed by two rounds of Book 2 space combat.
Originally the crew was making to exit the system, but communication with the Tukera vessel convinced them to support the Tukera fighters.
So, I had the player's ship and some fighters fighting some Sternmetal fighters using Book 2 combat.
The players had a vested interest in Tukera winning the day, not only for the reasons I listed, but also because they may be in real danger if the Sternmetal fleet came gunning for them.
They kept an eye on the progress of the fight, and as it started to look like Tukera was going to lose, they began moving away from the combat.
Sternmetal fired a few shots, but they had no real opportunity to get the PCs.
And, off the PCs went, to an uncertain future, their "side" having just felt a damaging blow.