Re: anyone has experience with carnauba wax?
have to agree with rliewky.... sealant topped with wax will give you the best of both worlds.
protection wise, most sealants last longer than wax... how much longer really depends on how often you wash your car... for example, a coat of P21s wax loses its shine after 1 week if you wash your car everyday (but then again it's a beauty wax)... the shine of 3 coats of zaino can last around 2 months in our climate, though it'll probably protect for slightly longer than that.
personally (not making a scientific claim here, just my personal observations), i find that sealants perform well in preventing oxidation but can be quite useless against bird bombs/water spotting.. though this could be due to the fact that you apply sealant less often than wax for most people.
looks is pretty much subjective... most sealants will leave a "glassy" look.. think of your car as having an additional layer of clear coat... i.e. very reflective... some people don't like this look as it can make a dark-coloured car look sterile or like plastic-wrapped/cling-filmed when it's too reflective (i.e. your eye tends to see the reflections instead of the colour of the car). This look can be desirable/great for white/silver cars though where achieving depth of reflections can be difficult.
wax, on the other hand, can give your car more warmth.. (e.g. the look of a car when you say "that black car really looks black!") which explains why some people see benefits of using it with darker colours. Furthermore, some waxes contain fillers, which can mask swirls (spider webbing) on dark cars... thus avoiding the need for an abrasive polish ever so often (you don't want to polish so often that you remove too much of your clear coat... twice a year is a good yardstick). A top of the line wax (zymol's concours, swisswax BOS and upwards) will also cost more than your top of the line sealant.
To achieve a really wet look, consider using a glaze to go along with your sealant/wax. You can use an acrylic based glaze if you're going the sealant route, or an "oil-based" glaze when using a wax. Some paint cleaners such as swisswax's, zymol's hd-cleanse, or p21, also makes the paint more wet looking.
hope this helps! cheers!