IMO, with all these fangdangled programs out there its just making things harder, Iv dont a few chassis, cages and 3 / 4 links, and never used any kind of programe, just sketched it out on paper. sure you dont get the fancy 3d, 360* view but thats what ur brains for. only time i have ever had "problems" is when people decide to make huge changes 3/4s of the way threw a build, but thats gonna fuk shit up weather you used a program or not
then again this is just my opinion and its easier for me to design a full chassis in my head then it is for me to even turn on a computer