I'm not a regular financial calculator user but I have several including a 14B. A while back I learned how to use them in the process of figuring out how to operate a TI Business Analyst (an LED model in the family with the TI57) without a manual. Later I tried to provide a comparison of the 12C and 14B for someone here on the Forum, and I became familiar with the more advanced functions. So I have reviewed what I learned to give you this comparison of the 10B and the 14B.
First, the 14B has 5 by 7 dot matrix digits like the 32SII instead of the 7 segment digits of the 10B. The annunciators are a little different than the ones on the 32SII, for one thing because the 14B has one shift key and the 32SII has two - maybe the 14B LCD is the same as the 32S.
The 14B uses menus. For a minute, I thought the 14B didn't do cash flow calculations because there is no "CFj" button but it turns out the cash flow list entry is done by pressing "NPV" or "IRR" at the beginning instead of at the end, these keys prompt you to enter a new cash flow list or use the existing one. The 10B lets you enter an initial cash flow plus 14 cash flow groups with up to 99 cash flows per group. The 14B lets you enter an initial cash flow plus 21 cash flow groups with up to 999 cash flows per group. I've always wondered how financial calculators stow away the extra few digits for the number of cash flows per group! Both calculators use some of the cash flow registers for storing statistics data but the 10B uses 6 registers in the middle of the cash flow list while the 14B uses 12 registers at the end of the cash flow list, so the 14B allows you to share them: if your cash flow list only has up to 9 cash flow groups (plus the initial cash flow), it will be preserved while you use statistics operations.
The 14B has three applications that aren't on the 10B: Return On Investment, Break-Even Analysis and Inventory Turnover Rate. The 14B has a "Compute" button (shift "Input") which is not on the 10B - it is used in the three special applications since their variables don't have their own buttons. The "Compute" button is also used in the "NPV" and "IRR" menus - since those buttons are pressed at the beginning. After you are satisfied with your cash flow lists, you press "Compute" to calculate NPV or IRR.
Both calculators do one or two variable statistics but the biggest difference is that the 14B does curve fitting with four models (linear, exponential, log or power) while the 10B only does linear regression. Under Statistics, Curve Fitting on the 14B you can choose one of the four models or let the calculator choose the model with the best fit. There is a separate Forecast menu that automatically chooses the model with the best fit.
There are some little differences in the way statistics are done in general. The 14B has a menu choice to display "b", the Y intercept (in the linear model, other values in other models); the 10B has you forecast the Y value for X=0 to get the Y intercept. The 10B has buttons for both sample and population standard deviation; the 14B has you calculate the mean and add it to the summation and then calculate the sample standard deviation, to calculate the population standard deviation.
The 14B had four independent storage registers, R0 - R3. The 10B has one, M. The 10B also lets you STO and RCL 0 - 9 and .0 - .4 but these address the cash flow/statistics registers.
Both calculators do conversions between Nominal and Effective interest rates which are important for Canadian mortgages. The 14B has three separate registers that are shared by this function and two kinds of percentage calculations and cost-price-margin calculations. The 10B has four separate registers plus shares the I/YR register to do pretty much the same bunch of calculations. The 10B has an explicit "Markup" button; the 14B does markup as an implicit result of the "% Change" calculation.
Because the 14B uses menus (mostly on shifted keys) to access some functions that are shifted keys on the 10B, some of these functions take three or four keystrokes to access on the 14B instead of two on the 10B - but on the 10B the second functions of function pairs (like "mean of X,mean of Y") take four keystrokes because "Swap", which is like "X<->Y", is a shifted function. The 14B doesn't have a button like "Exit" on the 17BII that always takes you back one level in a menu (although the "backspace" key does function this way in the multi-level menus but only up to the point where you select a bottom level function). So, for instance, it takes three keystrokes to calculate the mean of X values and then another three keystrokes to calculate the mean of Y values on the 14B compared to two keystrokes for the mean of X and then another two keystrokes for the mean of Y on the 10B. But this is alleviated in the Forecast and Statistics, Fit menus of the 14B when forecasting X or Y values for your entered Y or X values - you can press the "down" button to enter another Y or X value without having to start over.
By now I think you can tell that I can operate these calculators but I'm not really familiar enough with the functions to be able to say which calculator has implemented them better!
I left out the TVM program - as far as I can tell it works the same on both calculators - both use "Interest per Year" (as opposed to "Interest per Period" on the 12C) and have a "Periods per Year" variable that defaults to 12 but can be changed. I don't know why the 14B needs 12 registers for statistics unless it is in support of the different models for curve fitting. The 14B has a "Show" button to display all digits of a number, the 10B doesn't.