I don't play Mongoose so I'm afraid I can't tell you if it's any good...
I just want to say thank you for posting a link to one of my books. I know the thanks is more than a year late, but ...
You're welcome. I know the welcome is 3 months late..
Hey OP, did you go ahead an use Mechs in Traveller, how did it go?
I still flirt with the idea of a "MechaTraveller" game, running the Interstellar Wars as if it was a Mecha Anime series.
Vilani using Mechs modelled on their gods (Ancient War Robots) against technologically inferior races to project an air of godlike firepower and instil a fear of Humaniti in aliens. The mechs becoming a symbol of the Vilanis divine might over the centuries and millennia.
The Terrans however, lack this fear and simply see large targets. Over time they adopt the Mechs themselves. It isn't enough to defeat the Vilani in a few battles, they must shatter the image of invincibility and that means usurping the symbols of their might and using them against them. [This way I can justify their use in a sci-fi game, despite the disadvantages and impracticalities of the form].
Of course I intend to Anime it up a bit. Vilani have numerous different hair colours for example. The neural-jacks that control mechs work better when adopted from a younger (teen) age. Emperor-to-be Hiroshi begins as a dashing but inexperience princess rescuing hero. There are dark secrets to reveal, maybe the Terrans aren't the good guys after all. You know, usual anime stuff.
I picked up Mekton Zeta for inspiration too. But the problem, as always, is too many projects I want to do and not enough time to do them. At the moment my gaming time is mostly taken up with falling in love with old school, basic/original D&D all over again.
But I'd love to hear about someone else's Traveller with Mecha game...