I closed it out on a Rock B on my 5th run with the ship -- oddly enough, the *first* time I had not picked up a transporter and played it as a boarding ship. I got a Burst Laser II and a Heavy Laser I in the first sector that worked with the Heavy Pierce so well that I decided to forget firebombing and go for a direct damage plan. In Sector 2 I picked up a free Breach Missile, and Sector 3 I bought a Weapon Pre-Igniter.
Once I upgraded weapons systems enough to use all my toys at once, it was a brutal offense -- a first-second breach missile into their shields immediately followed by 7 points of laser damage to their weapons pretty much instantly crippled everything I faced. I also had a Scrap Recovery Arm, which didn't exactly hurt.
Later on I picked up a Burst Laser I and a Hull Laser I and went straight laser spam, which easily carried me through the boss, no drones or teleporter needed -- and I ended up with my second highest-score ever (5297) and over 30 drones and 50 missiles still in my back pocket. It was quite a satisfying way to get the last win

Weirdly, I got the Crystal ship *months* before I unlocked my last ship, the Slug. I went out of my way not to spoil myself on how to unlock ships and had no idea the Crystal ship was as rare as it is until I started reading forums. I eventually had to break down on the Slug ship unlock, though, because the game goes out of its way to stress how untrustworthy Slugs are, so every single time a Slug begs for its life I kill it just to be on the safe side. Apparently not a good strategy for unlocking the ship.
Even though Slug was the last ship I got, Rock was the last ship I won with because I get super frustrated with how slowly they move. Faster Than Light, my ass.
Anyway, I just had to share with people who would actually understand why tonight is the greatest night of my life. I can now go into Advanced Edition with my head held high!