I bought a BenchMaster to V-nail extraordinarily large frames on-site, in the client's living room. It's great for that kind of application, and installs V-nails just as accurately and securely as any other machine.
But because it's painfully s-l-o-w, I wouldn't recommend it for production, where labor time typically costs more than the equipment and consumable parts. If you're joining more than 5 frames a day, then you could easily justify the cost of a pneumatic V-nailer.
Example: If your shop labor rate is $50.00 per hour (which might be average these days), your production time costs 83.3 cents per minute. A pneumatic nailer could easily save ten to fifteen minutes per frame, compared to using the BenchMaster. That amounts to a labor savings of $8.33 to $12.49 per frame.
At that rate, you could pay for a $1,200 pneumatic V-nailer in about 144 frames, or maybe as few as 96.1 frames.
If you build 5 frames a day, payback might take about a month. And after that, the savings would be all yours, and you'd be able to grow your business more efficiently.
The best tools for the job don't cost -- they pay. The BenchMaster is probably the best tool for V-nailing frames in the living room, but not in the shop.