I bought a SPIT Pulsa a few months ago, second hand off ebay and an overhaul kit, as I had just won a job to install a complete smoke detection system: I work alone, so wanted something a bit faster than drill/plug/screw every 250/300mm.
BTW, the gun cost £275, and the fixings for the whole job were nearly £700.00, but I reckon I saved about a week/10 days (entire job was 3 months, then another 3 weeks for extras).
After some initial fiddling, the gun worked perfectly for 8+ hours a day, in brick, concrete, wood, and I beams (steel). This alone would make me buy a SPIT/Paslode nailer if I needed one. The gear is A1 + indestructable and the tech. support via phone is fantastic. BTW the best place (cheapest & good service) was Sitebox.