1. Sharp spine:
pro:
--> Perfect in the kitchen if your SO has the peeler in use.
--> Scraping of birchbark to have very easily flammable dust / bark shavings
--> Every scraping duty that will dull your edge
--> throws nice sparks
contra:
--> Hotspot for your thumb when putting pressure on the spine
--> If Carbon Steel - develops rust more quickly than a rounded spine
2. Scandi Grind:
pro:
--> Cuts very deep into soft wood. Whittling a fresh fir branch with a "thin" scandi is just a revelation.
--> Easy to produce and therefore "cheaper" - A Mora Basic is less than 10 dollars and a very capable knife.
(Mora has been making V shaped blades since the 60s' and before that concave - source: E-Mail from Mora company owner to William Collins · 10.06.2017 - Google: scandi grind - William Collins)
--> Easy to sharpen on a flat stone, no need to guess the angle.
--> Quick to add a microbevel - wonderful whittling and less prone to chipping
--> If splitting wood, wedge effect - splits wood easily
contra:
--> If you chip it, the regrind will take very long
--> Stropping will round the edge
--> If the blade is too thick, you have a sharp wedge and not a knife
--> Cutting carrots or other hard veggies is just not a good idea. /Wedge effect
3. Lanyard hole (fixed knife)
pro:
--> the knife won't fly out of your hand when you chop with it.
--> You can take only half the handle in your hand and have more chopping power.
--> If you need both hand to tie a knot, the knife is still very much reachable while dangling
--> if the knife has a thin handle, use the lanyard to get a "fuller" grip.
contra:
--> if the lanyard hole is too big, or not properly rounded - Hotspot danger after long use
3. Lanyard hole (folding knife)
pro:
--> you can attach a lanyard to make it easier to retrieve it from your pocket.
--> if the knife has a thin handle, use the lanyard to get a "fuller" grip.
contra:
--> none that I can think of
4. Round handle:
pro:
--> Freedom of grip - strange angle needed? No problem.
--> No hotspots or anything, its round...
contra:
--> Not easy to know where the sharp edge of the knife is, when you need to work in the dark.
5. No Choils nor Guard
Here no pro and contra, just some thoughts:
--> Choils are imho stupid - Snags on stuff you want to cut - wasting edge length at the most powerful and controlled area of the blade (Hammer grip)
--> If you place your finger onto the choil and cut something - it may be your finger gets in the way of the material you want to cut.
--> No Guard: Knives without a guard are most likely not made for applications where a stabbing motion is involved.
6. General Thoughts
--> Bladeforums is an amazing pool of knowledge - just think of a feature you don't understand - type it in the search and you will find a plethora of good information and discussion down to the tiniest detail.
Hope this helps.