Actually, i dont find seasalt spray being oily in any way. Perhaps its just me but i rate it based on dryness instead of oiliness. Because seasalt spray contains alcohol, it tends to dry the hair which i believe most people who use OS Fashion Sea Spray will not be unfamiliar with.
Aspect #1: Dryness (Subjective to say higher or lower the better)
Eco Seasalt Spray is definitely not as dry as OS Fashion Sea Spray. Not sure if its due to the concentration of alcohol used, but to be honest, the dryness of OS Fashion Sea Spray is fine to me all along. If you find OS Sea spray too dry, one can comfortably adjust the number of sprays the very next time. Personally, its precisely because of this approximate extent of dryness that allowed me to be able to style it better. When one's hair moisture is there, the weight will be higher and hence, you might find yourself requiring and using more styling products to make it more textured or whatsoever .
OS Fashion Sea Spray: 4/5
Eco Sea Spray : 2/5
Aspect #2: Bunching up of Hair (Higher, the better)
For those who used OS Fashion Sea Spray before, this aspect might not be unfamiliar to you at all. One amazing thing that OS Fashion Sea Spray can do for you is that it bunches up your hair very well. So why is this aspect important then? Prior to styling, when your hair ends are bunched up nicely and not divided loosely, it helps in terms of styling whereby subsequent application of wax/clay can help to achieve what you want much easier. With that said, your hairstyle will look more natural whereby it will be more textured/layered. If you're looking for tousled look, it helps to effect the messy look too. Imagine if your hair is not bunched up together, it will be like few strands of hair ends here and there (it will be awkward, of course), so this is also the reason why some ended up by applying more styling products when the desired effect and result cannot be achieved that easily.
OS Fashion Sea Spray: 4/5
Eco Sea Spray : 2/5
Aspect #3: Natural Waviness (Higher, the better)
This is more for people with permed hair, i feel. Although Eco Sea Spray lacks the aspect of bunching up the hair, i realized one good characteristic that Eco gives me is the natural waviness in the hair. It tends to bring out the curls and waviness in my permed hair better than OS Fashion. Most probably, its because its not as dry as OS Fashion so one is able to achieve better and natural effects for one on this reasoning. Good when you are heading out to the beach with some beach look. I thought its some marketing gimmick at first, but it definitely sounds legit to me after using it for about one week or so.
OS Fashion is too dry to bring me any form of waviness plus it bunches up the hair so no form of natural waviness is being created. In simple words, tradeoffs at the end of the day.
OS Fashion Sea Spray: 2/5
Eco Sea Spray : 4/5
Aspect #4: Smell (Higher, the better)
This is one subjective aspect that i need not further explain. To me, Eco Sea Spray wins hands down towards OS Fashion Sea Spray. My brother said it reminds him of perfume. I don't think it feels like perfume to me though but one thing for sure is that it emits a stronger and much lasting fragrance as compared to OS Fashion. Both has nice fragrance, to be honest. But OS Fashion's light fragrance will be gone pretty fast. Eco Sea Spray's fragrance managed to stay on my hair for quite a reasonable amount of time. For those who have a weak spot for fragrant stuffs.
OS Fashion Sea Spray: 3/5
Eco Sea Spray : 4/5
Aspect #5: Holding Factor (Higher, the better)
I chose to talk about this as the last aspect because it is the most intuitive and basic aspect that everyone will know about for seasalt spray. Hold factor for OS Fashion is slated to be 4/6 on its packaging. There is no stated hold factor for Eco Sea Spray. For this criteria, i guess there is no further debate required because after using both products, OS Fashion Sea Spray gives much more significant holding strength for one as compared to Eco. And precisely because of this functional advantage, one can also feel that the volume created for OS Fashion is much more and better than Eco. The "pom pom" effect is therefore much more evident.
OS Fashion Sea Spray: 4/5
Eco Sea Spray : 2/5
All in all, i feel OS Fashion Sea Spray is for the first timers who feel like trying out seasalt spray and be amazed with the impressive effects. I dare not say all but perhaps, most (including me) is pretty much impressed by how good seasalt spray can be. No more flat hair anymore. Eco Sea Spray follows behind closely because its does not seem to be the one that most people hope to achieve with seasalt spray. The voluminous effect is lacking for Eco but do not underestimate the tousled and wavy/beach effect that it brings for one. Both for different roles and purposes in different settings.
Note: There are really a lot of brands out there (e.g. KMS, Tigi, Vantachi) but once again, these abovementioned aspects are some criteria for judging seasalt spay in totality. Just to share, i used vantachi sea spray 350ml before and i don't really want to talk about it. Basically, it did nothing for me. I hope my 2cents worth of opinions help.