Firstly, anyone who argues over d10s vs d6s isn't someone you should be listening to when it comes to whether a game-design is good/bad.
![:P](https://static.mwomercs.com/forums/public/style_emoticons/default/wink.png)
That tells me they don't know much about actual game design/theory rather than just RNG systems (which in-and-of-themselves aren't games). So I really wouldn't factor die-type into whether or not one edition is better than the other, and honestly I'm not sure any edition of MW is so significantly different than it will affect the overall outcome of your campaign, even if certain aspects might cause minor inconveniences or bothers.
Secondly, what do you want your game to be about, in the abstract? I find Battletech lore neat and all that, but when it comes to tabletop RPGs, it's good to have a system that backs the group's creative goals for play (story, challenge, etc.). Having a super-detailed mecha system is cool, but that's not going to help give the game "oomph" if you're going to be focusing on elements of character and drama.
So like, if you don't care about story (other than it being a series of events/encounters) or having neatly balanced challenges for the players but just like the equipment lists and the technical details and how all that stuff goes "boom" when it collides, I'd say go for MW or some other system that focuses on that stuff (like One-Roll Engine Mecha).
If you want to focus more on elements of character and drama, I'd recommend using Starblazer Adventures (the FATE system) or The Solar System which include explicit mechanisms for encouraging that type of play -- both are merely toolboxes, so you can import any fictional stuff easily. Characters in FATE are made up of Aspects that define them rather than stats, ie, Han Solo might have "I know a few maneuvers" which he could use to get a bonus on a roll to avoid hitting an obstacle or a defensive roll against enemy fire while piloting the Millenium Falcon. There are also "stress tracks" (similar to damage tracks) which are used to decide whether a character is "taken out", which is interpreted as whatever the GM wants (a character only dies when the GM/group decides it's okay), and you can take consequences (ie, a broken leg) to reduce stress and avoid being taken out. The "FATE fractal" is the concept of applying these aspects and stress tracks to various scales of beings and organizations, meaning you can apply them to almost anything, including organizations and ships/vehicles, as well as story/plot related things. Your merc corps' actions might increase the tally on an opposing organization's stress track, bringing the game closer to some dramatic event on the plot stress track! There might be multiple stress tracks for a galactic organization's military strength, trade, etc. Play around these aspects is driven by a fate-point economy, which act like bennies, allowing you to utilize aspects (whether your own, or using an enemy's weakness) and assign bonuses, etc..
So while it may not focus on the teen-tiny details, you can still use the system to emulate Battletech well enough. You could assign aspects to your mech's technology to emulate how it works (an aspect like "Hotter than Hades" might mean your mech heats up quickly when attacking, which would be a great way to earn fate-points for invoking the disadvantage, which you can then use later to bump your attacks or advantages).
Really, FATE is super-easy to hack, and there are some great resources and hacks already available online.
For a more "fair challenge" type focus, I don't know of any systems for mecha, but I think Savage Worlds is a little easier to balance than most other games, if only because of the simplicity. Like FATE, there are tons of fan-hacks and resources available all over, and chances are somebody has already done a Battletech hack.
Edited by lincolnsmash, 29 April 2012 - 04:32 PM.