does this have a noticeable smell? i get headaches from hair product fragrances often, and i dont want any from this spray.

I get migraines. This product does have a scent, however, it is light and fresh. I find it hard to describe, although it is not fruity, with a heavy flower... It doesn't leave an odor in my hair. Maybe I don't notice it. I am very sensitive to scents and avoid perfumes. It is not sticky and I use it on dry hair to freshen up as well...

Do I have to blow dry my hair w this product? Can I air dry?

I do not blow dry. I just air dry then style my hair and spray it into my hair while dropping my head so to spray underneath, then let dry for a minute before reshaping. It adds volume and control to my fine hair.

Anyone there who has very thin hair and used this product as well as the swept up volume powder spray? which one gives better volume?

I love this product on my thin, dull hair! I got it as a sample from Sephora I think and now buying a full size bottle. It had given me volume and does not grease up my hair. I have oily hair and lots of products just feel heavy and too greasy on my head. Not this one! I also use maximista thickening spray right after I wash my hair and then I spray the texturing spray when blow drying my hair. I blow dry my hair with the revlon brush dryer, I find that it also helps with volume. I hope this helps.

Does it feel sticky or soft?

My review was not highly favorable; I had used the product only once and thought it left my hair feeling dirty, not really sticky. But I used a smaller amount just at the roots in my crown the next time and I decided I really love this product! My hair is soft and I don't feel the "dirty" feeling I thought I did the first time I used it. Maybe less is best. I absolutely love this product and will have to find a way to keep affording it.