Zwo AM5 Harmonic mount drive Pros No counterweight required for under 13 kg payload Mount is around 5.5 kg. Impressive tracking No need to balance the DEC axis Cons Rely on ASI AIR to work properly still need a hex key to adjust your altitude pitch angle from 45 to 90 degrees I have seen a broken azimuth lock-up handle Polar finder shoe Price tag Around 2300 USD when including the tripod, hand controller (estimate BOM cost of the mount is usd 900 or less) use of synchronous belt is to increase contact area between the stepper gear and strain wave gear, thus increase the energy efficiency(98% typ). At the same time it also eliminate slippage, but transfers vibration too Ioptron HEM27 Hybrid mount Pros IPolar finder included Mount is around 3.7 kg, lighter than AM5 No counterweight required for under 13.5 kg payload Similar ( slightly worse) tracking, probably due to slightly larger backlash from DEC stepper belt motor Cons Around 23...