I don't have a 10B, so I'm not sure about this part, but I *think* the 17BII has a lot more solver formula space/ability and appointments (you may use the appoinments only once every couple months, but when you need them it seems you need them)

As odd as it sounds, I use a 17Bii for the kitchen and the formula space is a really nice thing for timing dishes, calculating ingredients, and adjusting quantities for meal population.

I've also programmed in a library of conversions that I commonly use (including a sort of fake out for handling the way materials are measured in workshops down to 1/32") If you want to get into the really gritty bits, you can even use conditionals in your solver formulae.

It's not terribly complex to learn how to use- 2 hours solid and you'll have everything you need to know learnd and a small library of solver "programs" input. (note also that the solve rhere has all the capabilities of the 19Bii, even though they aren't all in the 17Bii manual)

Formula progam space in the solver (expecially 7KB of it) is what makes the 17Bii the best choice for me, but I don't know if the 10B had a reasonable amount of that. I seem to recall it not having conditionals, at least.

I understand the display cna be a bit bothersome to some people, but I've managed to solve that for desk use by making a mini "calculator wedge" that gives me a ~ 15 degree sloped non skid surface. I use this with my 42S, too.

The 10B just.... lacks power. I'd almost go with a TI ba35 at that point, too. *shrug*