Damn time zones : how dare people be awake and active while I'm at work on the other side of the world!
In all seriousness, that was quite enlightening, especially from the jihad/dark age defenders, I can't say I'm thoroughly convinced (but personal tastes can only be discussed up to a point) but I got to see opinions from the other side and would probably be less negative about these eras if I had to rewrite the original post.
There is just one point I would like to clarify about the starting era thing. I don't want to start a debate, after all I'm not sure to be particularly representative of every newcomer nor to even be right (and I'm not sure there is a right opinion on this), I'd just like to show you how I, personally, as a beginner, feel about this.
I have seen several posts arguing that the starting era could absolutely be an ulterior one, based upon two main classes of arguments :
1) Even if there is a bit more fluff to learn, it is only some pages more on the universe primer. Perfectly manageable
2) Even if you want to know "what happened before" there will always be things that "happened before" for every era.
Well, these are probably fine arguments for the persons you are, no problem with that.
But that's absolutely not the way I saw things when I wanted to start playing BattleTech.
=> the "it is only a few pages more" part
Well, there was this game, famous for its expansive 'verse and engaging fluff. So... well... I wanted to enjoy it! I was absolutely not about to content myself with the few pages of the universe primer : I was going to play BattleTech, I was certainly not going to ignore one of its main appeal, which is its rich background.
So, I explored the store and sarna to understand the deliciously convoluted range of books (where it is somehow completely acceptable for something last printed when the Berlin Wall fell to be the most current source about a major faction) and I understood they could be classified by "eras". With only the main sourcebooks and the most significant novels of the succession wars, I was already looking at hundreds of pages (maybe more). Add the Clan invasion : about the same quantity.
And then the Jihad and the Dark Age : dozens of novels, sourcebooks etc.
I hope you can see my point : no, starting in the Jihad is not going to only add a few pages. If you actually want to enjoy the fluff (and I'm not talking about every obscure sourcebook, "touring the stars" or novel : the main documents will be enough) you are actually adding hundreds of pages. And to me this really is an addition : I don't think you can seriously start learning the lore only with Jihad or Dark Age era stuff : the Star League and ComStar sourcebooks and the houses sourcebooks/handbooks are the real heart of the setting.
I don't think that every newbie should be expected to read a lot of stuff but neither should they be expected to just be happy with the primer when they've been sold a game with a rich universe. This is an integral part of the BattleTech experience. I can tell you that one of the first things my friends told me when I talked to them about the game was about "yes we know 40K is not the best ruleset in the world, but the lore is gigantic and awesome!" (yes they also said "is it not the game with ugly minis?" but we know things got better), one of my main selling point was that BattleTech was not subpar in terms of fluff and I myself was attracted to it because I like that kind of 'verse (I learned to love feudal space opera with Dune then Fading Suns).
=> the "there is always something before" part
That is absolutely not the impression I was under while reading the succession wars sourcebooks. Each of the houses sourcebooks and Star League and ComStar actually are the starting point as they contain the absolute beginning of the storyline : their lore start with the Soviet Union (by the way I love these delicious "alternate universe" snippets, indeed this is not "the future", it is the future of the 80s) and constitute an excellent basis to the BattleTech universe by telling you how Terra colonized the Star, started Brexit on a galactic scale, created the Star League, had to use giant stomping robots to convince people that it was a peaceful endeavour and, in the end, learned why you should always watch Star Wars Episode III before crowning a loner boy with a weirdo friend.
Granted, you have all these supplementary books allowing you to play during the Star League but these are clearly optional (though quite welcome for the already knowledgeable player) and their lore is already quite adequately shown in the main sourcebooks : these are good starting points, they give you a solid grounding in the Battletech universe and can be read without prerequisites, while Jihad books for instance are really more enjoyable if you already know the Houses, the Clans and the history of the rise and fall of the Star League.
And that is why, beyond personnal tastes, I favour a succession wars (and maybe clan invasion) starting point : you really have a lot less material to digest before knowing the lore adequately.
Now of course, furthering the timeline is great for people who've been playing for decades. If I had been playing BattleTech when Melissa Steiner and Hanse Davion got married, I too would like some changes! But as a matter of fact I was quite busy getting potty-trained at the time and had no time for interstellar politics.