Well, correct me if I'm wrong but AFAIK it is still the first victory on CE and "Hard" difficulty level that we know about:http://s13.postimg.org/hkfr2p347/ce_hard.jpg
What a super-hyper upgraded Red Tail (with all systems and weapons one can dream about) wasn't able to do, was done by only moderately equipped Mantis B aka TheShipThatMostPeopleCryAboutBeingUnderPoweredInCE, aka TheInFactMostPowerfullShipInFTLCeOrVanillaDoesntMatterAsSoonAsYouManageToGetPastFewStartingSectors
If you still think boarders are underpowered in CE, take a look at this winner equipment, and ask yourself, what any other ship would be able to do with so laughable weapons (BTW, adaptive was bought in Sector 7, replacing Hasta, and Artemis missile - the one that Kestrel starts with - on sector 6, replacing... Leto.). Sure, it was a lucky "barely" win (I managed to avoid damage at 2x last boss superweapon outbursts, a single stray hit would send me into the all-to-known junkyard)
Anyway, to make boarding anyone and everyone a piece of cake, I installed hacking system, which in 90% of cases was used to hack enemy's medbay, after luring full enemy staff there, by sending Mantises there. After activating hacker, as you may imagine, it was a quick bloody bath, even bigger than average episode of GoT
Via the same method - just after destroying Ion and Beam - I've eliminated crew of Flagship in phase 1. Crew of countless Rebel Cruisers and battleships meet the same fate on the way through all 8 sectors.
Ah, the thing important to mention is that I've bought Zoltan Bypass unit in sector 7, which helped greatly in phase 3 (and "helped" seems like an epic understatement, I suppose, considering how long it took me to neutralize zoltan super-shield, even without saving rockets). BTW, the first attempt at phase 3 started with Flagship disabling my - of course - teleporter, so I jumped away (leaving flagship to happily pound Fed base a little), and returned, this time getting shield weakened, as seen on picture. Anticipation boss fight, I've produced something like 35 rockets in various beacons of sector 7, via ammo manufacturer (it was a nebula, so many empty sectors), which I was carrying with me since sector 5, almost not used before.
All in all, the final fight was a tough one, but the whole run almost relaxing - to the point that I was almost certain that I can't win it, as it goes too smooth.
Thank you, Sleeper (and all people credited) for creating CE and making a win on hard the thing that *really* feels like an achievement!