Thanks for everyone's input...I just took the plunge.
I ordered several True Blast Plus upgrades from Trainworld, and took advantage of their weekend sale.
Will let you all know how it works out, the upgrades will be a good wintertime project.
I already have four of the newer WBB units: the PRR 44 tonner, the Anniversary Genesis, the Seaboard Also RS3, and the ACL GP30 which all came with True Blast Plus. So I am familiar with it, and I am impressed with the sounds.
These new upgrades should improve the rest of my herd. I have used the Williams dummy upgrade kits a half a dozen times in the past to add two motors to my B units, I was always impressed with the well written instructions, simplicity of the install, and plug and play setup.
PS I see the new GG1s are in the stores with True Blast Plus, hopefully upgrade kits will be released soon for my older GG1s and EP5s.