Hamilton Jazzmaster Open Heart AutovsLongines PrimaLuna

The Hamilton Jazzmaster Open Heart Auto is noted for its dressy yet versatile design, featuring striking gradient dials and intricately shaped cutouts that reveal the H-10 movement. It boasts an 80-hour power reserve and Nivachron hairspring. The watch is available in 36mm, 40mm, or 42mm stainless steel cases. On balance, the Hamilton Jazzmaster Open Heart Auto is appreciated for its visually engaging dial and movement display at its price point.

Owners widely praise the Longines PrimaLuna for its stylish, understated design and comfortable 26.5mm and 34mm case sizes, with some preferring the quartz for its lower maintenance and others the automatic for its craftsmanship. The automatic movement, an L899.5 or Caliber L899, offers a 72-hour power reserve and exhibits consistent accuracy averaging a loss of 1.3 seconds per day in testing, though it runs 3-4 seconds slower on the wrist. The redesigned collection features a curvier case with contemporary lug integration and is available in steel or bi-metal. On balance, owners and reviewers appreciate the Longines PrimaLuna for its elegant styling and reliable automatic movement, though some find its brand prestige and design less compelling compared to certain luxury alternatives.