We have tested both the Dolphin Sigma and the Polaris Freedom in real pools, measured their suction at the intake, and lived with the filtration and daily routine each one requires. This comparison brings those results together so you can see the real-world trade-offs without relying on the numbers printed on either box.
This is also a corded-versus-cordless decision: one prioritizes continuous power and scheduling, while the other removes the cable but adds charging.
The short answer: Dolphin Sigma is our pick. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin. Meanwhile, the Polaris Freedom carries a not recommended call in our review and is only relevant for Polaris loyalists whose first priority is avoiding a cord.
Quick Answer
Buy the Dolphin Sigma when its strengths match your pool. Best for: buyers who want near-Premier power with full app control. It is the stronger choice across the measurements and ownership factors that matter in our testing.
We recommend skipping the Polaris Freedom for most pools (its 0.8 psi is the lowest cordless reading in our canonical set, followed by a four-to-six-hour recharge.), unless your single overriding priority is Polaris loyalists whose first priority is avoiding a cord.
Our calls in the full reviews are Recommended for the Dolphin Sigma and Not recommended for the Polaris Freedom. Those calls matter here: PSI is the first round, not the entire verdict.
Suction Power: 2 PSI vs 0.8 PSI
On our hydro manometer, the Dolphin Sigma measured 2 PSI and the Polaris Freedom measured 0.8 PSI. That gives the Dolphin Sigma a 1.2 PSI advantage, or about 150% more intake pressure than the lower reading.
We measure pressure directly at the intake with the same gauge and pool setup. That is different from manufacturer flow-rate claims in gallons per hour: GPH describes water movement, while PSI shows how hard the intake pulls on debris. Cordless results are recorded at full charge. Our complete pool-robot suction test explains the method and shows where both robots sit on the full board.
The number needs context. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin. It covers the main pool surfaces and its filter basket is easy to reach and rinse. The stronger gauge result gets this round, though intake pressure alone cannot make up for a filter that lets fine debris escape or a routine that makes you handle the robot every day.
Filtration and Debris Handling
The Dolphin Sigma uses top-loading pleated nanofilter cartridges for fine dust, pollen, and silt. The Polaris Freedom uses basic top-access mesh basket.
We give the filtration edge to the Dolphin Sigma. Our comparison favors fine-particle capture, usable debris capacity, easy cleaning, and whether the better filter is included rather than sold as an upgrade.
For leaves, capacity and intake design matter. For pollen, silt, and the haze that dulls otherwise clear water, the filter media matters more. A basic mesh screen can look clean after a run while still passing the smallest material back into the pool.
Automation and Daily Work
The Dolphin Sigma is corded. MyDolphin Plus app works underwater and supports weekly scheduling. The Polaris Freedom is cordless. Four app modes, but every cycle still ends with retrieval and a long recharge.
That power difference changes the ownership routine. The corded robot can keep full power through the cycle and run from a schedule when its controls support one. The cordless robot removes the floating cable, but it must come out of the water to recharge. For frequent cleaning, that usually means deploying and retrieving it every day.
The automation round goes to the Dolphin Sigma.
Coverage and Pool Fit
For the Dolphin Sigma, our review found floor, walls, and waterline with the widest intake path we have measured. The Polaris Freedom is built for floor, walls, and waterline without a cable.
The Dolphin Sigma wins the coverage round on the breadth of surfaces and pool situations it can handle.
This is where the runner-up can still be the smarter fit for specific pools. A compact pool does not benefit from paying for reach it cannot use, while a pool with a sun shelf, long waterline, or heavy leaf load can expose the limits of a simpler machine quickly.
Value: Performance for the Money and Time
Our value take on the Dolphin Sigma: Expensive, but it combines elite suction, filtration, navigation, and app control. For the Polaris Freedom: Convenient on paper, but the lowest measured suction and daily charging weaken the case.
The value edge goes to the Dolphin Sigma.
Value is not the same thing as the lowest checkout price. We count cleaning power, filtration, how many surfaces the robot covers, and how often you have to retrieve or charge it. A cheaper robot that leaves you vacuuming behind it is not a bargain, and an expensive robot only earns its price when its extra capability solves a real problem in your pool.
Which One Should You Buy?
- Buy the Dolphin Sigma when its strengths fit your pool. Best for: buyers who want near-Premier power with full app control. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin.
- Skip the Polaris Freedom for most pools: Only consider it for Polaris loyalists whose first priority is avoiding a cord. Its 0.8 PSI is the lowest cordless reading in our canonical set, followed by a four-to-six-hour recharge.
- Know the main drawback: Dolphin Sigma — Its premium price is hard to justify if a power-supply timer is all the control you need. Polaris Freedom — Its 0.8 PSI is the lowest cordless reading in our canonical set, followed by a four-to-six-hour recharge.
Final Verdict
Dolphin Sigma wins this comparison. Dolphin Sigma wins the overall matchup. Its 2.0 PSI reading, wide intake, NanoFilters, and underwater app make it the most complete connected Dolphin. Polaris Freedom remains the better fit for Polaris loyalists whose first priority is avoiding a cord.
Read the complete Dolphin Sigma review and Polaris Freedom review for every test photo, setup detail, and long-form ownership note. You can also return to all pool-robot comparisons to see any other matchup from the 19 cleaners in our test set.
