Custom Training Plan versus Standard TR Plans

My current A race goal is a 3.5 hour MTB race in early May. I just completed the SSB low-volume II series and have 16 weeks remaining… enough for the XC Marathon Build phase and Specialty phase blocks. What are the pros/cons to creating a custom training plan when I have enough time to complete two full blocks prior to my race? Which one will have me better prepared for my race?

Thanks in advance.

Have you considered the recently release Plan Builder?

It is one way to allow TR to run the scheduling, and is more or less “custom” to fit your events and time table.