I went through this about a year and a half ago. Like you, 8x10 contacts just seemed a little smaller than I wanted. I found an 11x14 Empire State that needed work, bought it, tore it down, refinished it, bought a new bellows and finally managed to find a couple of film holders. Already had lenses to cover, but I've added a couple more in the last year. The camera, at 15 lbs, doesn't weigh much more than my 8x10 (12 lbs). I have not yet done a lot of shooting with the 11x14 mainly b/c I don't yet have my darkroom set up for the bigger equipment I need to process the film. However, I will in the near future get the dark room set up and will do a lot of work with the 11x14.
So far, I do have some experience with it in the field. I'm not so concerned with being limited to shooting near the car or with backpacking the camera--first, there are a lot of great locations I can drive close to; second, the total weight of my 11x14 gear is not much more than my 8x10 gear. The real limit is cost and availability of 11x14 filmholders. Unless you want to pay $350-500 each for new ones, that is. Even this is not a real limitation as I can live with making only 4 or fewer photographs per outing with the 11x14 for the time being in order to gain the bigger contact print size.
I am having to come up with some modifications to support the camera. Unlike my 8x10, the Empire State does not allow me to center the weight on the tripod so I have to be more careful that the head is tightened into position. I also had a fright last week when I set the 11x14 up in gusty winds. The whole rig was blown over by a sudden gust just as I reached for the film holder; I barely caught it before camera and all came crashing down on the rocks. So I learned to set the tripod up with legs extended wider than I do with the 8x10 and to set my camera bag down wind of the camera. Point is, the ULF is bigger, heavier (duh) and working with it will require a little more thought, learning, and patience. Again, to me, the bigger neg is worthwhile.
In fact, I skip the 8x10 format for bw; I use the 4x5 when I plan to enlarge and when I want something lightweight and easy to handle, and I use the 11x14 when I want to make contact prints.
To continue with the analogies (I liked the poetry one, Bruce), I look at ULF as having a sports car in the garage. It's a lot of fun to take out on occasion, and seasonally it might be your main vehicle, but it's probably not going to be your only vehicle or even your main one most of the time (unless you live in Southern Cal).