One thing I will add that the other reviewers did not mention is that this stapler packs a heck of a wallop. The power of this lightweight unit really amazed me.
The truth is, I did not know what to expect. I have never owned an air-powered stapler or nail gun. I planned to use this Hitachi stapler to put up kraft-faced insulation, and then later use it for trim work. Yeah, right. I loaded it with 0.50" staples. They went right through the paper tabs on the insulation and kept on going into the studs. I had to look hard to find them because they had been sunk so deeply.
I turned the air pressure down to 70 PSI, which is the minimum operating pressure and set the stapler's depth adjustment to minimum. No dice. Too powerful! I went back to using my Arrow T-50 Carpal Tunnel Syndrome Special.
I decided to get to know this little monster better. So I ran a test to see what it could do. I loaded it with 1.50" Senco staples and fastened a piece of 7/16" Oriented Strand Board (OSB) to some wall studs in about five seconds. Extremely impressive! I showed my science project to my wife.
She said, "Very nice. Now take it down. It looks terrible stuck up there."
I tried to pull the test piece off the wall with my bare hands, but it would not budge. Then I tried to pull it off with a 22 oz. framing hammer. That didn't work either. Finally, I had to use a 3-foot long pry bar. Geez, talk about embarrassing.
My last futile effort involved trying to recycle the test piece of OSB by attempting to extract the 1.5" staples I had shot into it. I won't tell you what happened except to say the OSB went into my woodstove, staples and all.
Here is a tip: Whatever you staple with this Hitachi stapler is forever.
UPDATE, October 2010: This stapler is still going strong. I have put up 1536 sq. ft. of 3/8" plywood using the stapler and have done various other jobs with it. I have run nearly 3000, 1 1/2" staples through the unit and have not experienced a single jam or other malfunction.
As for maintenance, all I have done is cleaned the unit with compressed air and sprayed some WD-40 on its moving parts. Of course, the stapler gets five to eight drops of air tool oil before each work cycle.
UPDATE August 19, 2012: Pushing 7500 staples and still going strong. One weird thing did happen about a month ago, however. I was happily driving staples into plywood when the sheet suddenly pulled away from the studs. At first I thought I was off the nailing line and just missed the studs, but then I got looking more closely at the staple holes and realized there were no staples in the holes! Yeah, I had run out of staples. I mistook the small indentions made by the stapler driving mechanism, about a sixteenth of an inch deep, for the staple heads.