Im not Bryan but have used alot of the Meguiars 105/205 and their PRC (Paint Reconditioning Cream) D151.
It is hard to compare a straight compound Meguiars 205, with the D151 product which is a light compound, polish and wax, but I can tell you this from my experience.
The PRC D151 product is a great 1-step product that is easy to use and finishes down nicely with a Rotary or a Random Orbital. In terms of its cutting ability, I would have to say that in my experience, its cuts to so far and stops, because its abrasives are gone, while the Meguiars 205 will continue to cut until you let off on the pressure, etc..
I really like the D151 for what it is - a fast way to cut and polish and leave a nice protected finish on a vehicle that is in for just a quick detail and go type of scenario.
I also really like the M105/205 products for what they are able to do on so many different types of paint/problems/etc., and their finished down shine is ready or about LSP ready for some jobs, and just needing a quick polish down with something else with a finishing pad on other more critical jobs.
Hope this helps !

Dan F