There are basically five different types of Fallkniven F1.
The first model was ATS34, a bit pointier and didnt have a protruding tang.
The second model was flatgrind VG10 but looks like the current ones.
The third was VG10 but had convex grind.
The fourth is the current, laminated VG10 and convex grind.
The fifth is 3G steel (collectors item)
You can watch the differences on
http://hem.passagen.se/nodh 
The difference in performance is usually beyond your needs anyway, but the Lam VG10 is the strongest one after the 3G.
Get a regular lam VG10 and if you dont like the convex grind you can get someone to regrind it for you.
The backside of a F1 is almost as sharp as a ice skate. The use of firesteel is not dependent on the material in the knife. It is only if you want to hack sparks out of the knife as in Ray Mears book.
I and many with me have used the back of the F1 to light many fires and since the steel is so hard it keeps both the knife edge and the back edges sharp for long time. The convex F1 is a bit fiddly to sharpen, but the tools are just a 800 grit paper and a mousepad or your own thigh
If you have any questions, dont hesitate to mail me. You can also visit the Fallkniven forum at
http://www.knifeforums.com/forums/showforum.php?fid/65/
where lots of Fallkniven owners will help you enjoy your great knife.
The F1 is the best for survival because it is big enough to do the job but still small enough to be carried everywhere.
There are 34 other Fallknivens in the range, and you can not have just one
The Swedish armed forces actually have most of the Fallkniven knives in inventory, the issued pilot survival knife is a satin blade F1 with a special plastic sheath (looks almost like a Mora sheath), many of these have M-number (NSN-number) engraved on them too. The first knife on my page.