Spherical stitching is very powerful, a good stitching head and tune it well for the nodal point and you get great results. I've have one myself for my DSLR. Nowadays I would only use it if my Schneider Digitar 35mm on the Techno would not be wide enough for a shot.
To me it's not really about quality but about workflow, I like to capture the scene in one shot. But if you'd want the highest possible quality at a budget, spherical stitching is clearly unbeatable. Post-processing work can be quite much more though as you need to manage many files, but if you're very structured in the workflow and use the fastest software it can be quite smooth.
I've also tried a 4x5 camera with wides. I'd say that focusing is not the main problem if you use some tricks (pre-focus at a fixed distance, have a strong flashlight in dark environments, using a very strong loupe etc), however parallelism can be an issue, ie it's quite likely that the front or back standard is put out of alignment so you get a fuzzy side. Most will certainly want to shoot tethered when using a view camera, due to ground glass darkness with wides in indoor environments. If you can shoot tethered it can be done say with a Sinar X in good condition and super-recessed boards, but it won't be that smooth. Compared to stitching it could be argued that it still would be smoother as you get less files to work with in post-processing.
