Yes, a field camera is not a whole lot faster to set up than a Sinar. I lugged a Sinar F2 around for three years. It was great for studio work and location shots, but backpacking it was not something I ever considered. Add weight for lenses, dark cloth, film holders, meter, filters, lens shade, and a few accessories. Then consider that a field camera weighs about 8-9 pounds less and folds up into a small package. It may be somewhat less versatile than a Sinar, but it makes sense for some.
Look at it this way, if you buy it and don't like it, you'll be able to sell it to someone else for what you paid for it. It's a buyer's market for Sinar gear, so you should be able to get it/sell it reasonably easily at the right price. The F1 model was replaced by the F2 more than 20 years ago, but the differences are small. In good condition, it will last for many years, but bear in mind it is not a new model. That should figure some into price negotiations.
Peter Gomena