There's PID and there's how you actually switch the power to the HBP. They are two entirely different things. Many firmwares default to using bang-bang for the heated bed regardless of whether they use PID to decide when to continue or stop heating. Sailfish is no different in this regard: it uses bang-bang for actually switching power to the HBP. And on all of my printers with Makerbot-style heated beds, it's only about 8 minutes to reach 100C. (And likewise for the ones with RepRap-style MK2a HBPs.) Me, I never use 110C but plenty of other people with those printers do since it was MakerBot's recommended temp for years. Ergo, your problem is your specific printer and not the firmware. And since this isn't a support forum, you might be better off posting to the relevant support forum for your make of printer. Odds are, there's something wrong electrically. If it's an Asian clone printer, often it's the really poor job of wiring and the power connector to the HBP is failing (burning up) on one end or the other of the wiring. (Far too many posts of exactly that in the assorted forums.) However, it may be that you have the wrong build of Sailfish on your printer. There's a special build specifically for FlashForge printer's with ATmega 2560s. They have a mis-manufactured HBP circuit which has far too low of a resistance and will attempt to draw 14.1A @ 24V (in a printer with a 14.6A PSU). So, FF modified the firmware to use PWM to simulate only presenting 17V to the HBP circuit. That sort of works. But if you use that firmware with a "normal" MakerBot-style HBP, then it will indeed seem to take forever to get your HBP to temp.