I use Kerastraight's Heat Protection Spray* (£19.00) all the time and I really do like using it. Heat protections sprays aren't the most glamorous of products to talk about but they're actually an incredibly important part of my beauty arsenal. When I don't use a heat protection spray you can really tell, my hair gets damaged far more quickly and my hair dresser gives me no end of grief about it!
I regularly blow-dry my hair and, more often, I curl my hair using my hair straighteners. Before I do either of these things I really do try and remember to use Kerastraight's Heat Protection Spray* - I just visualise the lecture I'll get from my hairdresser if I don't. I spray about four sprays on either side of my head, usually spraying from about 30cm so that a fine layer of product is evenly distributed across my hair. I then have to wait a minute or so for the product to soak into my hair (the only downside of applying a wet product to dry hair) and then I get on with the business of heat styling.
I've been using Kerastraight's Heat Protection Spray* for about a year now (since January 2015) and I'm consistently happy with the results. It's never weighed down my fine hair or left it looking greasy, and I do really believe that it makes a difference to the health of my hair when I use it before heat styling. This being said, I haven't tried any other heat protection sprays since I began using it and I don't have a great deal of experience with other heat protectants so I can't compare it to many other products. However, from the strength of my own experience I would definitely recommend it as a product and I would repurchase it over the other heat protectants that I've used in the past.
Look Fantastic stock Kerastraight's haircare range and regularly offer great discounts and deals, so if you're interested in trying anything from the brand then I'd point you in that direction.