For residential and small commercial I prefer solid wire. It's easier and cheaper to terminate on switches and outlets.
For larger commercial and industrial I use stranded wire. Most of these places have a lot of vibration from equipment.
I do not consider romex to be stiff. Larger sizes are just harder to handle size 8(appprox. 5.486 mm) or 6 (approx. 6.452 mm). ( size 8 is limited to 50 amps @ 75C and size6 is limited to 65 amps @ 75C.)
[This message has been edited by nesparky (edited 10-19-2002).]
