Thanks for all the kind words, guys.
I am such a sucker for Breakdown's colorscheme in vehicle mode. I don't know what it is, really: The blue "lining" all the way around the edge, the red trapezoid on the hood, the red stripe on the top of the roof or the general white/blue/red combination. Of all the projects I've ever done and/or started on, Breakdown here is still my absolute personal favourite (I find myself actually playing with him on a regular basis!
Regarding Motormaster, I have most of the parts I need to start on him; I just want to complete the others first. Need to experiment with the correct scale-adjustments between vehicle and robot mode, as I don't want him to be a giant compared with the other 4. He will still be substantially bigger than the others, though -- that can't really be changed.
"More on this as it develops..."