I've basically decided on some 27" swampers instead, just do to the lack of availability of the Simex tires. Not that I'll be buying anything any time soon, but I liked the idea of a Simex brand tire, when I first saw a pic of them in a magazine.
I did see that webpage but they don't have Extreme Trekker nor Jungle Trekker II, all they have is the all-season highway radials (at least for the light truck applications).
I have heard praises about the Extreme/Jungle (in Indonesia), even mentions about shower of huge chunks of dirt from them, comparing to shower of pebble-like clumps of dirt produced by Super Swamper. They are supposed to be cheaper than Super Swamper (again in Indonesia) but the price list I have found showed otherwise.