I see that there is a significant difference between the razors that have a solid edge to them and the others that have like little feet on both sides. What's the reason for these differences, and which one is for what application? Is it just personal preference or is there a functional reason for the difference?
I find the open comb (little feet) tend to rinse cleaner if I have longer than usual growth like after an illness if I haven't shav3d for a couple days. They look more intimidating to me, but if you're using proper angles shave the same as safety bar razors.
Open comb vs Solid bar all depends on the razor. What I have seen is the older Gillette's that were Open Combed were more aggressive than the Solid Bar Gillettes. Modern razors are a whole new can of worms.
Once you have good technique a raxor is a razor. On open come looks neat. It tends to clog less if you have more beard to cut. That being said a solid bar does the job just as good. Open comb does not mean aggressive by the way. They are a lot of fun to shave with.
No, but it is handy on my laptop for occasions like this. http://jrshaving.blogspot.com/2017/06/gillette-new-improved-being-replated.html
Love both of my vintage Gillettes with the "little feet"(I love that by the way). NEW Short Comb ca. 1932-40 1911 OLD Type And like @Jayaruh I keep pics handy for situations such as these!