Both of the blades are very strong, both in regards to the tip and the main body of the blade. While the Busse may be a little thicker, the S1 has a more obtuse grind and stainless steel is very strong. I would bet on the S1 to have a greater break strength than the Busse, but again both are very strong and will easily handle very heavy work .
In regards to corrosion, VG-10 being a stainless steel will resist rust better than M-INFI in the Basic. However I have never had any problems with INFI of M-INFI in regards to rust with only light care. The worse has been some light spots of black oxide after long term exposure to salt water (soaking for hours).
The Basic will likely have better edge retention because of the Nitrides in the steel as well as the increased toughness. However the S1 is hardly poor in this regards it will do a lot of work before it needs to be touched up. It however does come with a convex bevel, which you can however easily convert to a flat one with a little work.
There will be a large difference in toughness. I have seen both INFI and M-INFI survive a lot of high impact work and flexing that would not bode well for a 59-61 RC stainless steel which are brittle and not that flexible. This is fairly extreme work though you have to be making contact with the blade with very hard objects or doing a *lot* of lower stress work (chopping / prying).
I would expect the Basic to outcut the S1 significantly simply because it has a thinner primary grind and has a lightly dropped handle. However the edge bevels may decide that which means if you are willing to do about 15 minutes work with a coarse stone, they will both cut at nearly the same rate.
The grips are very different, Kraton is not as durable in regards to wear and tear nor chemical attacks. It is also more abrasive than the Busse Combat grip, but slightly more secure becuase of the same reason. Neither grip is that secure when it is oiled/soaped but both are functional when wet.
Both blades impressed the hell out of anyone I showed them to (Basic #7, S1).
Busse Combat blades carry a full warrenty, the Fallkniven ones do not (I think there is a time and abusive clause).
-Cliff
[This message has been edited by Cliff Stamp (edited 02-28-2001).]