Don't forget the type of alloy used to manufacture.
2618- Low silicon content, high expansion rate requires a large piston to wall clearance. Generally a nitrous or drag piston since the alloy looses strength (becomes brittle) after repeated heating/cooling cycles. These are usually noisy due to large piston to wall clearance.
4032- Higher silicon content, low expansion which allows you to run "stock like" piston to wall clearances. Normally much quieter that 2618. This is considered a daily driver forged piston. Not as strong as the 2618 but still much stronger than cast. They will survive repeated heat cycles better.
FYI I have a set of 4032's. No noise, no oil consumption.