If you can find a Nagaoka or Anba-Ikeda in good shape, and your intent is to use it for backpacking (or other travel applications where weight and bulk are concerns), I say go for it. I've had both. I started with a Nagaoka (with chrome plated hardware nd a black bellows) and "upgraded" to an Anba-Ikeda (shiny brass plated hardware and red bellows). Other than the color scheme and name, the only real difference is the top rear focus is geared on the Anba and not on the Nagaoka. This is no big deal as you can still use the front geared focus for fine focusing. This "feature" adds a couple ounces to the weight.
If backpacking is your goal, it's tough to beat the Nagaoka/Anba-Ikeda. Not only is it extremely light (between 2.5 and 2.75 lbs), but it also folds up smaller than any other 4x5 camera I've ever seen. This means it takes up less space in the pack than other cameras. As a backpacker, I tend to be an ounce counter and to me the difference between a 2.5 lb. camera and a 6 lb. camera is very significant. The lighter camera also means I can use a lighter tripod and head combination as well - it all adds up. Currently, my camera, tripod and head have a combined weight of 6 lb.
Of course, I also minimize the weight of my other photography items (carbon fiber tripod, magnesium ball head, 3 or 4 ultralight lenses, Quick/Readyloads, etc.). When I first started backpacking, the total weight of my 4x5 camera gear was 25 lbs. That included a 6 lb. Speed Graphic. These days it's about 1/2 that - around 12 - 13 lbs. and that includes enough film for a 4 day trip and the daypack I carry the camera gear in. I'm not as young as I was when I first started backpacking with a large format camera, and believe me, my knees,back and shoulders appreciate the weight savings.
About six years ago, I upgraded my backpacking camera again. These days, I use a Toho FC-45X. After a few simple modifications, I got the weight down to the same 2.75 lb. neighborhood as my old Anba-Ikeda. The Toho has about 3" more extension, full front and rear movements and is more rigid than the Anba it replaced. It also cost 3x what I'd paid for my Anba. IMHO, the Toho is the best 4x5 backpacking camera around. That said, many of my all-time favorite images were made with the Anba.
I wouldn't recomend the Nagaoka/Anba as a general purpose 4x5 camera. When weight isn't an issue, I prefer a camera with a longer bellows, more movements, smoother operation, better ease of use and greater rigidity. However, for backpacking, it's tough to beat (unless you buy a Toho). For this reason, I always find myself owning two 4x5 cameras. One for backpacking and one for everything else. It used to be the Anba combined with a Wisner Tech Field. For a while I tried a Canham DLC as my ONLY camera, but then decided to go back to a two camera system - the Toho combined with a Linhof Technikardan TK45S. These days I'm using the Toho for backpacking and very long day hikes and an ARCA-SWISS F-Line Field for everything else (the ARCA chassis also serves as the base platform for my 4x10 and 7x17 cameras). I find this gives me the best of both worlds and is the ultimate evolution of all the camera combinations I've tried over the years.
In any case, if I didn't have the Toho, I wouldn't hesitate to go back to a Nagaoka/Anba for my backpacking camera. It's not pefect (no camera is), but it's plenty good enough and excels as this particular application. Just don't overspend on one. If you're patient, you should be able to find one in excellent condition for around $400 - 450. Anything higher and your getting close to the cost of a new Tachihara.
As far as durability, I used my Anba for backpacking for 10 years and never had a problem. I just wrapped it in my darkcloth and tossed it in the daypack with my other camera gear. Other than an occasional loose knob (as dmax mentioned), I never had any problem. If I still had it, I'd probably just dab a little clear fingernail polish on the threads near the end of the shafts to keep the knobs from falling when the camera is bouncing around in the pack. After 10 years of pretty heavy use, the finish on the camera showed signs of use, but it still worked as good as the day I bought it. Again, not the camera for all users or all uses, but a pretty good match for your intended application.
Kerry