In fact, either copied a "mentor's" model (btw, this mentor has no background in underwriting) or paid some Internet guy $100 to download their underwriting model i.e.

Give them a call and they can point you toward someone who, for a few bucks, will take a look at the specifics of your situation and give you a better answer than some guy (me) on the internet.

It's more costly but it's very convenient for every user and more efficient if set up properly. 

What are the benefits to this type of system vs. one with traditional internet? 

Personally I didn't use RE Agents but I always computed the cost anyway.

There are "turn key" wife companies all over the internet. 

I have a rehab analysis spreadsheet uploaded in my file place which includes a Repair Estimator & Rehab Calculator to help you estimate repair costs and analyze the Max Purchase Price you should offer for a rehab.https://www.biggerpockets.com/files/user/drobertso...There are other good spreadsheets in the fileplace, or BP has their own web-based calculators.

I put a snapshot of the long term buy and hold spreadsheet I stole off the internet and modified to suit my needs(I hope you can read it, it is kinda small).

I'll use rent roll $ rather than units as it's not fair to SD to say "I want to build a portfolio of 1000 units" because that's much easier to do in Houston. 

They are very user friendly.