The Norma is my favorite field camera. But now in my 70's, I will admit that for airline travel and long mountain backpacking trips, I now use a lightweight Ebony folder instead. Arcas are very well liked by certain outdoor photographers, but seem way overpriced compared to what Sinar offers in even better-featured fashion, at least nowadays, since clean used Sinar gear is abundant. I still have my Sinar F2, which is somewhat lighter and more compact than a Norma, and was easy to transport to projects. I stopped doing commercial architectural shoots sometime ago, back when my former clients starting renting digital MF gear. Once digital took over, everybody demanded the results almost yesterday, and clients wanted to look over your shoulder like vultures and pontificate on what they saw on the screen. I have no patience that kind of annoyance, and stood out from the crowd by charging per print, not per job. They sought me out for both my reputation as a printmaker, and for my expertise in architectural color consultation. Now I still take opportunistic shots of interesting buildings etc, but for personal interest, for sake of both color and black-and-white darkroom printing.
The Arca has fine enough gearing for modern digi backs, but as you no doubt know, those backs are really med format at best in terms of capture area, and require shorter fussier lenses than 4x5. A friend of mine still uses his Sinar P's for studio work, now with digi backs, and has no problem with fine focusing - and he's the most successful studio photographer I've even known in terms of sheer income. The best known career architectural photographer here in northern Calif. used the Toyo VX ever since its inception, but switched over to an Arca MF digital camera due to need-it-now scheduling, and regretted it - not due to the excellent gear itself, but due to the micromanagement vulture mentality of the clients, like I just described. Good luck with your choices!