I use the 3 Rivers one, but Stu Miller helped build it. I can't say if its easier or not, but it has always done very well for me. The only caveat to it is that you have to get the data exactly right. I'd say try the 3 Rivers one and see if its easier to work with. For shaft diameter for 11/32 you input .34375, but everything else is very self explanitory. Ignore the personal form calculator at first, in the future:
If you have a set up you KNOW works for you, but the dynamic spine spread is off too far, + or - the personal form until the 2 numbers are +/- 2. Thats your personal form number. So for example, you input your current set up data and calculate but you come up with a spread of 49 / 50, if you subtract 1 (or whatever) on the personnal form and it makes it 49 / 49, for future set ups just subject the 1 to the form calc. And that would be your "true" reading.
If none of this is remotely helpful I'm sorry