Quick take
HYDRO 4 SE is worth considering if cable-free deployment matters and the pool size fits its cycle time. Buyers should compare filter-basket design and wall/waterline performance against similarly priced robots.
Why cordless matters
Cordless pool robots are faster to deploy and easier to store because there is no floating cable.
The tradeoff is battery aging and the need to ensure one charge can complete the intended cleaning cycle.
What to compare
Look at stated pool-size coverage, cycle length, wall-climbing ability, waterline cleaning, filter fineness and debris basket volume.
Do not assume every robot marketed for “walls” also performs well at the waterline.