My own takes on the eras go like this:
Age of War: Just kind of "there", and much of it was BattleTech without the BattleMechs, meaning the most unique thing about the setting isn't even present. It is interesting from a "how we got here" standpoint to be sure.
Can't resist saying more about that era.
The thing with the age of war is its "introtech potential".
The battlemech (in its primitive form) only sits out the first 60 years or so of this 170 years long war. By 2490 everyone has functional battlemechs ready for combat.
Now, primitives are but a gimmick, kind of stuff that while interesting, I doubt many use them. But late age of war offers the perfect setting for introtech: few mechs, few weapons and the "ares convention" effect which fits snuggly whithin the whole BT mechanics. It would be perfect to ease in new players. This is also true of a rejuvenated space battle aspect of the franchise.
We know the major factions all had fleets, but little beyond that. It could be fleshed out as seen fit and would, again, make great introtech for a "battlespace 2" or whatever.
Then there's all the "niche products" within the franchise. From battleforce on, the "gentle man's war" of post-ares age of war (which is pretty much all of it) is again a perfect setting. And with the early phase, I bet you could make an interesting game out of the "abstract combat system" with all the combined arms plus the use of tactical nukes, chemical weapons and orbital bombardment. But again, most if not all of it are but niche products whithin a niche, some even whithout the main draw of the universe.
Lore wise, I know there's quite the few of us battletech enthusiasts whom love learning about minor factions. I loved the small Hindu Collective rundown in "era digest:age of war", I'd bet many others appreciated it.
So yeah, much potential, if mostly in the introtech and/or niche departments.
Also, the dragoons indeed. The 4th SW breaks what is pretty much a centurys long stalemate and the 'goons are THE pivotal unit. The 4th SW would've been very different whithout the marik civil war, which would've been simply impossible whitout the dragoons, and then they litteraly tie up the only other major contender in that war. Hanse's deck was stacked, and yes, he did play very well to stack it up... but in all fairness he was dealt a fabulously good hand as soon as he sat at the table.