Manada Airsoft does a technical comparison between the Rossi Neptune Short and the Rossi Sentinel airsoft rifles highlighting that the primary functional difference between the two models is the trigger system. The Neptune Short features an electronic trigger, which provides a response similar to a mouse click and allows for faster successive shots. In contrast, the Sentinel utilizes a mechanical contact system. While the Neptune Short does not include a battery, the Sentinel often comes with one, though the performance of both rifles can be modified by using either 7.4V or 11.1V batteries to adjust the rate of fire and trigger response time.

In terms of external design and build, both rifles share a similar body and gearbox reinforcement. The Sentinel utilizes an M-LOK handguard, whereas the Neptune Short is equipped with the older KeyMod system. Testing shows that both models produce nearly identical performance metrics, with both recording approximately 1.3 Joules of energy and consistent feet-per-second (FPS) readings when using 0.28g BBs. This suggests that the internal ballistics of the two platforms are comparable despite their different price points.

The price gap between the two models is approximately R$1,000. The analysis suggests that the choice between the two depends on a user's priority regarding the electronic trigger versus budget for external accessories. While the Neptune Short offers a more advanced trigger out of the box, the lower cost of the Sentinel allows for immediate investments in optics, stocks, and other customizations while maintaining similar muzzle velocity and field effectiveness.