Stopping mechanism

If you've never seen the saw in action you can watch a video at the SawStop web site. Fine Woodworking magazine hosts a video where the hotdog is pushed at a faster rate here. The bottom line is that this saw cuts you about 1/16" for every foot per second that you're moving.  If you hit the blade while feeding the wood you're likely to get cut about 1/16" or less. If you hit the blade while you're falling you'll likely get a 3/16" deep cut instead of multiple finger amputation.  If you hit it while pitching a baseball for the major leagues the injury will be even worse.

It works by shoving an aluminum cartridge into the spinning blade.  The cartridge is spring loaded and always ready to go. When the saw senses that you've touched the blade it releases the cartridge into the blade and lowers the blade below the table.  The energy in the spinning action of the blade helps cause the blade to drop under the table.  You can read more details here. (Side note: This is one of the reasons Miter Saw Stop would be difficult.  Even after it stops the blade you have to prevent it from breaking all your fingers.)

The blade is triggered when it senses that it's touched something with more capacitance than wood. Capacitance is your ability to store a charge.  Wood has very little capacitance but humans, being mostly water, have a much higher capacitance.  The saw would also be triggered by metal, other meat products, etc.

You need a separate cartridge for dado blades.  If you attempt to run the saw with the wrong cartridge it senses that the small cartridge, designed for a 10" blade, isn't close enough to your 8" dado blade.  The saw does not work with a 6" dado blade. Changing the cartridge is a tool-free operation that now takes me less than one minute.  It's difficult to see and the first time I tried it I spent over 20 minutes trying it, referring to the manual, trying again, etc.

Riving Knife

A riving knife is similar to a splitter in that it prevents the wood from closing on the saw blade or more importantly from moving back onto the blade and kicking back to the operator.  A riving knife is better in two critical ways.
1) It rides very close to the blade.  When you cut a normal 3/4" board with the blade just above the wood you have about a 4" danger zone between the back of the blade and the splitter. A riving knife cuts this danger zone down to 1/8".  A splitter can not be this close because it doesn't move as the blade is raised and lowered.  A riving knife does.
2) It doesn't extend higher than the blade.  This means that the riving knife can be left in place for non-through cuts.

Dust Shroud

Guys on the web has given the dust shroud a lot of attention. (Note: The door in that picture is removed.  It would make the side of the shroud much higher.)  In my opinion, it's not warranted.  I appreciate that somebody tried improving dust collection (DC) on cabinet saws but I haven't notice a big improvement. Also, the cabinet on my unisaw never needed cleaning because the DC port was at the bottom of the cabinet, where the dust gathered.  This saw gets most of the dust but sometimes it requires me to go in there and scoop out the dust it missed. (Note: It's rare but sometimes I make quick cuts with the DC turned off.  That contributes to the missed dust but it's something the unisaw would just pick up the next time I turned it on.)

Table top

 The huge table doesn't get that much attention on the web but it makes a big difference to me. Normal cabinet saws have a table that is 27" from front to back and about 36" wide. This saw's top is about 30" x 44". That adds to it's huge weight but it also helps support stock to the left of the blade.  Also, jigs that rely on the the miter slots have 3" more before the guide leaves the slot and enters the wide slot of an outfeed table that doesn't keep the jig steady. This extra large cast iron table contributes to the extra weight this saw has over the PM66, General 350, and the Unisaw.  The rest of the weight probably comes from the larger mechanisms inside the cabinet.

Alignment

I didn't test the saw the day it arrived but I did test it later on.  I had 0.000" run out at the arbor.  I couldn't believe it so I broke it down and tested it twice.  I can not detect any arbor run out.  The blade was 0.005" out of alignment. I can't tell if it shipped that way because I had lifted the entire saw by the table several times to get it off the crate and onto the mobile base.  Also, I had mounted my outfeed table on the back of it.

Normally, to adjust the alignment on a cabinet saw you loosen the bolts that hold it on then start banging it around with a mallet.  The SawStop is much more refined.  There is a screw driven mechanism that moves the table under control.  This allows you the control to get it really perfect (or at least as perfect as your test plate is).  For example, you start at one end of the plate and zero the dial indicator.  Then you slide it to the other side. Let's say it moved 0.006".  You're 0.003" out of alignment.  Now slide the table so that it reads -0.006" and you're done.  Retest and tighten the table top back down.

Motor

 I bought the 5hp motor from SawStop.  I've cut deep dados in hard maple with a negative tooth dado blade and it never sounded like it was challenged. On the other hand, I don't recall every wanting more power from my 3hp unisaw. Still, I'm happy to have it.

Miter Gauge

The miter gauge is the nicest OEM miter gauge I've seen. It holds its setting when you tighten it down, the handle is comfortable and doesn't feel cheap, and the indicator line for the angle is easy to read.

Kill switch

Everybody knows that you're supposed to unplug your saw when you change the blade.  However, it's enough trouble that sometimes I skipped it.  The SawStop has a kill switch that has the same impact as pulling the plug from the wall.  It's a real nice feature and it's one of the things that makes me think the inventors are trying to address all the known problems with cabinet saws.

Power Switch

The power switch on the SawStop is more sturdy than the unisaw and it's nicely angled toward the operator.  It's clear that they designed it to be bumped with your thigh at the end of the cut, which has become second nature for me. The switch also has indicator lights which have about 12 codes of different blinking patterns.  These codes tell you if your cutting wood so wet that it would be hard to detect a human touch, they tell you if the blade is still spinning down, if the cartridge is properly installed, etc.  When the blade isn't spinning you can touch it can observe that the saw detects your touch. Note: If you just touch the tip of the carbide lightly with a dry hand it won't detect you.  If you wet your finger and touch the tip again it will.  Broader contact with the side of the blade is easily detected.  Playing around with it like this has taught me that you're going to bleed, just not as badly.

The quality of cut

Photo of my SawStop

The Good:

The Bad

Conclusion

This saw is often compared to the Unisaw, General 350, and PM66. However, it's nearly 150 lbs heavier than any of them, it has a larger table, and advanced technology.  It's really in a class by itself.