Comenting on the Spire is just like commenting on the Ninja Pro Reg when it came out. Played with a friends spire 260 for a couple of weekends now and what can I say. Almost identical size to rotor, Lighter, never jams, Low Battery Indicator (great on batteries anyway), the most amazing speed feed and excelent build quality.
What is most importantly, particularly as a back player is the amount of balls it holds.
From experiance:
Rotor holds 160-180 balls realistically which means 16-18 seconds of laning and initial shooting.
Spire holds 250-260 balls realistically which means 25-26 seconds of laning and initial shooting. And thrust me it makes a huge difference, not to mention there that you can comftorably dump a full lock lid with 80-100 balls still left in the loader. Im in love!