I remember Wes going counter to the longer-lived perception of elves as presented in modern fantasy such as Lord of the Rings, or D&D (the latter which I believe prevalent in most people's mind).
For instance, I say the elf has the advantage of time on the neko in that a playable elf has had a childhood... but I don't think the time to reach adulthood is any greater than a normal humans. Nor do I feel they were as infertile as the usual trope regarding elves indicate they are. Otherwise their prior enslavement and exposure to the 'Elysian plague' would have torn them down to an unsustainable level on grounds of their gene pool permitting reproductive perpetuity.
On one hand, I figure they'd have had to be fertile enough to compensate for lost lives (Hanako being taken in by Yui practically saved her life, a lot of other elves were far less fortunate, hinting to me that the rate of mortallity was high).
On the flipside, if elves are indeed not that fertile and not bio-diverse enough to 'recoup' their population, this could also have interesting impacts. Firstly, every elven lives would be precious and it would be contentious for an elf to go to war. Secondly, it would reinforce the reality that the elven territories are a preserve of natives for more reasons than just low numbers. Also, there could be a clash tradition-wise before that reality and the interest of some to go to greater lengths to preserve the species; from medical procedures forcing insemination and pregnancy, to genetic re-engineering. They could also struggle (like they kind of do now) to actually have relevance in modern Yamataian society because they're members of preserve of natives whom are frail, less educated (hard to beat downloaded machine learning as a convenience), and less capable than even the ordinary Minkan - especially in contrast to the warlike culture Yamatai has.
The civilian-side of Yamatai, up to the Senate, could be solicitous to the elves for the sheer sake of feeling good about themselves. However, most of the higher placed Star Army characters often allude to the perception that they find the civilian-side of the Empire's population coddled and disconnected from what actually needs to be done to assure their safety (a safety that, in turn, allows the civilians room to complain in the first place). Elves are stock within the civilian-facet of Yamatai that's the least able to contribute to war, and that may carry an unspoken kind of stigma.
Of course, an elf could learn to fight as an art. Fighting arts could have been practiced and handed down through generations. A master, on an academic level, could be possible. But is there actual value in the Star Army for the rare individual that is so super skilled he might be invaluable, but still could be killed like anyone else by the simple vaguaries of war? Whereas, neko soldiers are trained just enough to get shit done. Veteran soldiers, even in the hands of PCs, are generally those that survived mistakes or avoided making mistakes while working in a team environment, rather than be a combat virtuoso. Of course, you can envision such an elven warrior-artist being a superb instructor... except that nekos might just go "Bitch, either I Sora Mai your face in, ventilate you with a NSP, or let a few dozen of my Mindy's drones take care of you."
A good Yamataian soldier is less her skills (which are acquired for free anyways), and more her decision-making ability. The latter is more something that ties to the roleplay decisions we do, than something we can tag as "oh, an elf would have more experience in this case". So, saying elves have that advantage is nice, but insustancial fluff.
On the other end of the spectrum is how long their lifespan is. Lifespan is a tricky issue, because there's so little of it that's actually relevant to the SARP experience, and there's actually little we can do to properly display a character with a lifespan greater than our own. So, giving an elf a greater lifespan is fluff, rather than a true actual asset were the SARP roleplaying experience is concerned. The most it will do is determine how far back a starting character will remember things... and many people here are actually iffy on the level of what could have happened before YE 27 because that's around when this setting really got to put meat on its bones. And the advantage of living further into the future are tenuous without a timeskip of somekind, and even more so if you consider that a neko could just swap bodies and essentially be immortal as long as the technology to mind transfer is present.
That concern aside, we know that the Angels (Elysians) were essentially the stewards of the 'fantasy themepark', and that they could live multiple centuries. I believe the answer I got to the question was "way back when, around 300+ years". Considering the angels were la-crème-de-la-crème where species on that world were concerned, we know that the elves lived for
less than 300 years. Based on that metric, I'd perceive the elven lifespan being something like around 200 to 250 years.
Bear in mind that Mind Transfering is derived from Soul Transfer, which was originally as Elysian (Angel) asset. the longevity of the Elysians could just as much be ascribed to them being able to create new bodies and swapping through them, earning effective immortality, whereas the 'elven savages on the ground' lacked such an advantage. Therefore, when we speak of advantages derived from long lifespans, the Elysians should stand as a pre-existing example of an upper-limit in that respect.
Edit: in light of the paragraph above, it could be that elves and elysians might both live the 80-100 years the human body seems capable of reaching if in good enough health; but that their boon is that they would retain youthfulness through the majority of their lifespan (i.e.: elves might only see the kind of decline we start having at 40-50 years old at around 80, and engage in a quicker decline, expiring around the next two decades while aging as to look like a human in his/her sixties - ailments of age could creep up on them, but only at the last fifth of their lifespan). Elysians would likely soul transfer around then, while the elf would be stuck just expiring in his only body.
As someone whom just turned 40, I kind of think retaining one's youth to his 80s, without the frailties and impairments of being geriatric, would be a pretty big deal and certainly something to envy.