As far as the steels go assuming both knives were exactly the same just with a difference in steels:
3G is laminated SGPS (Super Gold Powder Steel) with 420J2 on each side for extra toughness.
- 3G will be easier to sharpen
- Will be tougher due to being laminated
- Should hold a better edge than VG-10 according to Fallkniven (that's why you pay more for it) However I've read some experiences and tests to the contrary as well as in support of.
S90V is also a powder steel with more carbide in it and very stainless
- S90V will hold an edge noticeably longer (whether 3G is as good as Fallkniven touts or not)
- It won't be as tough, but still tough enough for a fixed blade that won't abused (I've used my Spyderco Phil Wilson quite a bit with no problems on wood, even with some light batoning with no ill effects and its pretty thin stock.)
- Both steels should be very stainless
- As for sharpening, S90V will be harder to sharpen than 3G but you will also sharpen it less often so for me it balances out, sharpen one steel once every two weeks for 5 minutes or the other steel once every 4 weeks for 10 minutes. (Also for me S90V wasn't near as hard to sharpen as I was expecting, it just takes more strokes compared to other lower carbide steels, strop it 25 times each on a strop instead of 12 (S30V) to touch it up)
I think there are two schools of thought, get a steel that's easy to sharpen and touch up in the field which will mean lower edge retention, or get a steel that has such great edge retention you won't have to touch it up in the field and you can give it a proper sharpening when you get back (even if you're on a 2-3 week trip and that is your only knife). I prefer the latter. Of course, you could also land anywhere in between as well.
Spyderco Phil Wilson in CPM-S90V and two Customs in CPM-10V at 64HRC (even harder to sharpen but even better edge retention)
