Hi - I also wrote a review on the Badger SPF 30 because I have both, but just wanted to highlight a couple of reasons why I love both the SPF 15 and 30.
Basically, it's the ingredients that make this a fantastic product (maybe that's obvious?). EVOO, beeswax, shea butter, cocoa butter, jojoba oil, essential oils, plus obviously the zinc oxide. See, for me, that's exactly the type of stuff I love using on my skin anyway. So it's super-handy someone added in zinc oxide for sun protection (including great UVA protection which, as the solar radiation most responsible for ageing, is clearly super relevant). Also UVA travels through glass :( so it's important to be using a daily sunscreen that includes good UVA protection. And I wouldn't be happy using a chemical SPF on my facial skin every day for... ever. So a natural product is much more realistic for me.
On the whiteness, I actually don't find it a problem for either the 30 or 15. I have olive toned skin and actually white products (or light foundation, for example) do look bad on me, but these aren't a problem. You have to let them melt in to your skin, and I do wear foundation / powder or bronzer on top most days, but not very thickly.
That's my two cents (or pence) worth! Love it.

The EWG just came out with their new sunscreen assessment on safe and effective ingredients and Badger was one of the few companies that made the cut. (If you search the web, there are various articles on the new report, and the report is also available on the environmental working group site) But for my ridiculously sensitive face (rosacea and dermatitis), "safe" doesn't translate to non-irritating with Badger's multiple ingredients. (Wish I could find a sunscreen with minimal ingredients.) It also feels on the greasy side, and doesn't tend to play well with makeup. In short, Badger may be a no-go if you have a very sensitive face, or if you need a sunscreen you can wear to work that will allow you to look professional. (For kids, it's probably a better deal and safer than some others.) Meanwhile, it has also been noted that sunscreen doesn't help prevent skin cancer that way hats and clothing do. And I've yet to find a sunscreen that will prevent my rosacea from worsening with sun exposure. Thank goodness I love big hats!

I wanted to find a physical sunscreen with zinc-only so I decided to give Badgers a try. I have been using it on my face daily with no problems. This is very thick- more of a paste than a cream. I squeeze some out of the tube and dab it on my face--rubbing gently to get rid of the white cast. Since my skin is dry, it don't feel that it is too greasy for me. I also think this suncreen sinks in pretty well. I use a primer over it and then apply my foundation. I have an olive/tan complexion and haven't had a problem with a white cast (probably due to the fact that I use foundation over it). It is no more "white" than some day cream/moisturizers like Jurlique anti-aging day cream. With this product, some will love it while others may hate it.

I wanted this to work on my face, but it clogged my pores. It's very thick and white, but it does rub in if you make an effort. It would be fine for arms, legs, etc. if it didn't take so long to rub it in completely. I like to use it on my neck and decollete area because it leaves a light sheen that makes my cleavage look great...sometimes I even use it when I'm going out at night just for the glow.

I wanted a good sunblock that I could wear everyday, instead of, not as well as, a moisturiser.
I have dry skin. I wanted a physical, not chemical block, and chose this because it got one of the best ratings on Cosmetics Database for it's purity of ingredients.
I read the reviews of the SPF30 and was worried about the white cast. I chose the SPF15 as this is a daily sunblock for me, something that I can wear all the time, and though I have super pale skin, I live in Northern England, which isn't exactly known for it's sunshine. So I decided SPF15 would be sufficient as daily wear. I wouldn't rely on it for going out in the sun though (even here, that's how badly I burn).
Unfortunately this product made me feel very greasy. When I first used it, it seemed to have seperated in transit, to a white paste, and, well, pure olive oil. I mixed it back together in my hands and applied it. I found it quite easy to blend, it's a lot thicker than many products, but not problematically so. I am pleased to report there was no white cast whatsoever. However, it doesn't feel it has sunk in at all (five hours later). I put my mineral make up on top, and it has made it very transferable (one of the reasons I like minerals is that you can't wipe them off accidentally). With this is a base my foundation has almost become like a liquid foundation. However my skin is very moisturised (perhaps too much!), I have found with moisturisers with added SPFs that they are too dry for and make my mineral makeup cake up instead.
So I don't know what I am going to do! Moisturiser with SPF is too dry, pure sunblock is too heavy.
I'm going to persever with it a bit longer, and will update if there is any change.
I'm not sure about under make up, but I would definitely recommend this as a natural physical sunblock that does not leave a white sheen.
UPDATE - I am definitely not going to use this on my face as it is too greasy. However, I love love love it for my body, it's so natural and moisturising and smells great. Have awarded an extra-lippie as it wasn't really specified for facial use so I can't be mad that it doesn't work there! Alround a great product.