Had a load of featheredge fencing to do so thought about one of these.
Asked a few professionals and they said the cheap ones are rubbish.
Took a gamble and ordered one anyway, arrived promptly band looked fine. Popped up to screwfix for a box of 5000 50mm nails (about a tenner) plugged it in to my weedy 25l compressor and away we went.
Although the unit doesn't feature adjustable depth it fired the brads thru the 20mm boards and into the Back rail perfectly.
Air use is negligible
Just don't miss and put one thru your finger as it goes straight thru and gets blood over your nice new fence, although it's not as painful as hitting your thumb with a hammer.
Used approx 1000 nails and it didn't jam or missfire once!
In summary, what a bargain and fantastic time saver