(I cannot say much about the XC end of it, but I would assume that what I am about to say still holds true.)

If you are an alpiner, put this on your skis for those colder days and it will help you ride fast the whole day long. Amazing durability even under the harshest, most abrasive man-made snow and ice on the mountain, thereby protecting your skis from base burn.

That durability comes at a price though and is the reason for not giving it a 5-star rating. Waxing is tricky sometimes since it is such a hard wax, and if you use this as a race wax (which in the NE you usually end up doing several times a year..) this is the hardest stuff to scrape and brush since the mid-90's Mach II Blue. Bring a sharp scraper!

Good Tip: For those days where you know it will be nasty abrasive, but a little warmer than 4 is rated for: turn your iron on low and run a very thin, controlled bead of wax down either side of your base, about 1 cm inside each edge. Then crank that iron back up, melt it in near the edges only, let it cool, give it a half scrape or a good brushing with a coarse brass and then wax for the temp you need. Provdes the protection against base burn when you are laying out the turns, but since the 4 takes up so little surface area on the base, it keeps the skis gliding fast when you are running flat skis.

Swix also makes a CH version that works just as well and is even cheaper!

I dont race but the speed of these waxes are so much faster than the cheaper waxes I am hooked, I will never go back to cheap wax...

I am trying out the rossignol S1 {182}.. Skate ski and ----- It seemed faster than the Germania 190 SX901 Skate....