For what it's worth Vertu is still around (www.vertu.com) and still selling phones to a certain clientele at places like Harrods and Dubai Airport. And with Android 6, Snapdragon 820, a 534ppi screen and a 3200mAh battery, they can at least hold their own against your average android phone.
As far as I understand the android fork on those phones is awful.
According to this review: https://www.androidcentral.com/vertu-constellation it's pretty close to stock android these days with a slightly customized launcher and a few minor tweaks like "Where a typical phone might offer only a few options for title — Mister, Miss, Doctor — Vertu Accounts offer a laundry list of titles, ranging from King and Queen to Sheikh and Lord and His Excellency"
Also the hardware is always a generation behind.
Hey they're improving. They used to be at least three generations behind.
