I have built a number of decks over the years for homes I have owned.  All of them have had real wood top deck boards.  Regardless of treated pine, cedar, the deck boards all had some amount of twisting, bowing, uneven edges, etc.  This year I needed to "re-deck" our old deck - 30' x 20' - that I built 20 years ago.  The CCA treated joists and posts were still in good condition, so I only needed to remove the old decking boards and install new ones.  We of course looked at many composite boards, but the only ones we liked the looks of were five times as expensive as real wood.  So, we chose the standard 5/4" x 6" real wood treated pine from Men-A-Rds.  I recalled from past projects the struggles I had in getting real wood to line up, and decided I might try this tool.  I looked for a few weeks on ebay but a used one never was listed.  So I purchased this new one from Amazon.  What a great use of my money!!!!  Because I was using real wood, most of which was still wet / heavy with preservative, I wanted to install my boards tight up against each other with no gap as they will shrink a little over time and give me a nice 1/8" - 1/4" gap once they dry out and shrink.  Once you get the hang of how to use it, regarding exactly where to place on joist to get tightest fit in locked position, you will love it too.  In my case, because this was a re-decking, and my deck is up 10+ high off of ground, I kept the existing old deck boards in place so I could stand on them, and only removed one or two old boards at a time, and replaced with new boards one or two at a time.  In some cases, where there was not quite enough space between and old board and new one to drop tool down onto joist, I used the old board as a support and then used tool to pry between old and new boards.  In most cases I was able to use one hand to "lock" the tool into place, in other cases once I put pressure on it I sometimes had to hold with one hand or a leg before I got my first screw in.  Regardless - it worked like a charm.  This is much better than other tools where you have to hold in place with pressure 100% of time, or pound some wedge device onto joist.  If you are thinking you might need or want this - don't hesitate - buy it.  I also purchased the inexpensive orange "jig-a-deck" plastic guide and that tool enabled me to easily and quickly get my screws lined up, so that they all look nice and straight and even.