Haligan: I, too, keep a flex bit in my truck. It has made drilling through wall plates easy and less-invasive. In fact, one time I bent a scrap piece of 3/4" EMT in to a 30-degree radial bend, made an access hole in a wall, and used the EMT to guide the flex bit straight through the wall plate to get into a basement. It was a situation where I could not drill up from the basement because the foundation was in the way and this wall extended beyond the foundation.

I have not used a 36" so like Capt Al said, you may have troubles getting it to go where you want it to go. I would think the longer ones would easier to bend while drilling, unless you're restricted by working space. [Linked Image]