The pistons connect to the shaft flange directly rather than pushing through slippers against a tilted plate, so side loading is much lower and there is no slipper film to leak across. Both volumetric and mechanical efficiency improve, and the design also reaches larger displacement angles.

Size, weight and through-drive. The tilted barrel makes the pump physically larger than a swashplate unit of the same displacement and complicates stacking a second pump behind it. Where the envelope is tight or several circuits must share one shaft, swashplate usually wins.

Closed-circuit hydrostatic transmissions, excavator main pumps and heavy travel drives - applications with long working days where efficiency shows up as fuel burned and heat rejected, and where the duty is severe enough that the extra robustness is worth the size penalty.

Somewhat, because there is no slipper-on-plate interface running on a thin film to be disrupted by particles. It remains a precision piston pump and filtration is still critical, but it is generally more forgiving of marginal conditions and shock loading than a swashplate design.

Yes, by varying the angle between barrel and shaft, and variable bent-axis units give the widest useful control range at the best efficiency of any type. They are correspondingly expensive and bulky, so fixed displacement is used wherever the control range is not genuinely needed.

Generally similar to or slightly better than an equivalent swashplate pump, though both are noticeably noisier than screw or vane pumps. Neither piston type is the right choice where quietness is a primary requirement rather than a preference, and on an indoor installation that consideration often decides the pump family before efficiency is even discussed.

Higher than a swashplate pump of equivalent displacement, which is one of the type's advantages and part of why it suits engine-driven mobile applications. The precise limit depends on the design and displacement and should be checked against the intended prime mover speed.