These are just my personal opinions, so here we go
I use a lot of scandi's which have a straight spine (no drop), they are lighter than most because they are stick tangs, they tend to be very easy to make and very cost effective.
Generally they are carbon steel (at least the ones that I use), but are not limited to carbon steel.
Now having said that I have a Helle Harding which is a laminate and is 12c27 (if I am not mistaken) this is a stainless and is a superb knife with a slight drop point. Stainless can be a swine to sharpen , but in recent years they have got better with the addition of new steels like S30V.
I also have a brusletto which I have had for over 13 years made in 12c27 also and it has a flat spine, it is easy to sharpen and holds a good edge and I love it to bits.
Stainless is good for it's corrosion resistance, in some cases like S30V, 12c27 it holds an edge well and is quite easy to sharpen, in other cases it can be a complete pig (the likes of D2, though to be honest I don't have too many problems with it). Generally Stainless is lower maintanence than carbon steel. You cannot strike sparks off the spine of a stainless knife with flint (rock type), however I have a strike - a - light and a firesteel so it doesn't bother me too much.
Carbon steel is easier to sharpen and you can strike sparks off the spine with natural flint, but it has the down side of virtually no resistance to corrosion.
Most of my full tang knives are drop points and I have them in a number of different steels, I have a couple of Gene Ingram knives (1 in D2 the other in S30V), I have a couple of Allan Blades (both in Carbon) and a couple on order (both in S30V), a couple of Fallknivens (both VG10 stainless) and a Grohmann boat knife (steel is german supposedly the same as 440A stainless) amongst others.
I personally prefer stainless knives, I live near the sea and salt is in the air that we breath, any damp on a carbon knife quickly turns to rust in this enviroment and I want something that will last me. I am willing to put up with the difficulty in sharpening some of them as a compromise.
I prefer drop points most of the time because I am a lot less likely to puncture the stomach or intestines if I am skinning using one, they also tend to have a little more belly which will slice better than a bullet point.
In many ways my ideal knife is the Fallkniven F1 because it is pretty much indestructable in normal bushcraft use, it is a drop point and it is a stainless blade, the spine is aggressively sharp when using it with a firesteel, but be aware this is one of the ones that I find a little more difficult to sharpen to a decent edge because of the steel (VG10).