It's very good. On heavier stains it's better than own label gels which give fairly average results at best, but are probably fine for everyday washing. Just don't buy it in Tesco, they charge a ridiculous £6 for the 16 wash bottle and £8.17 for the 24 wash size. Another rip-off from Tesco.
Cleans well, way too sudsy though and a swine to rinse out, especially in your soft water! Also I found it put holes in cotton items such as T Towels and T Shirts. Also if you own any items made of bamboo DO NOT USE Ariel gel, they will fall apart after a few washes.
I have a Culligan water softener and I only fill the Ariel gel dosing thing half full maximum. No problem with stain/odour removal or rinsing at that dosage particularly at 15/30 degrees.