You're right, basswood is stronger. Also a bit heavier.
I find it easier to cut with a power saw or oscillating blade. An Xacto blade will wear your fingers out.
I have cut plenty of basswood by hand. The Ragnarok was all 1/8" basswood, which was indeed pretty hard to cut, but at least they were straight cuts. Since then, I've used 1/16" and 3/32" which cut without too much problem for me. Yeah it's a few passes but no biggie. When cutting basswood, I usually use my larger Olfa snap-off which gives a lot better leverage. I wouldn't normally use an Xacto #11 or anything like that.
My own personal experience with Basswood it that it tends to break easily, parallel with the grain ( gets worse, as you go thinner ). If I need strong fins, either thin aircraft plywood or home-made "balsa plywood" gets the nod.
I agree; basswood seems weak parallel with the grain. However, in a recent build I glue-papered some 3/32" basswood and man that felt *really* strong.
Other pluses and minuses for basswood:
1) It's harder to sand. BUT it's also harder to oversand, which is nice
2) It is MUCH more resistant to getting dinged up from handling. You don't have to treat your basswood fins with kid gloves. This include sharp edges (e.g. airfoils or beveled or whatnot). That makes it much less stressful to work with.
Overall, I still use balsa most of the time for LPR, but basswood definitely has its uses.