This was written by Spartans very own Kane and posted here with his permission and a little editting by me (adding videos)...

I just got my Airsoft Innovations Tornado Grenade in last night and wanted to give you a few initial impressions.

The first thing I noticed is how much smaller it was than what I expected.  From the website it looked like the size of a flashbang, but when it arrived it was definitely hand grenade sized.  It fits nicely in my average-sized hand and can easily be handled by a smaller hand, like that of a young adult or female. 

Next I noticed how light it was in comparison to how it looked.  I actually feel safe playing with it and not giving come poor player a concussion when I toss it overhand into a pillbox or room.  Even with it full of BB's (roughly 180) it still isn't heavy at all.  It has just enough heft to allow you to get it where you want it and not pull a muscle while trying to do so.  You can toss this thing a long way.

Ok, on to the mechanics/build.  The body looks like is is made from glass nylon, and it actually 2 halves surrounding the metal internals.  The sides are attached together with 8 small Allen screws and also "glued" at the seams with an ruddy-brown epoxy-like substance.  I say epoxy-like because the small bit that is showing is still pliable, like really strong rubber cement. It looks a bit like an afterthought to keep inquiring minds from disassembling it, but who knows for certain.  The last big plus is the intentional lack of a “spoon”. You know, the part that flys away to be lost forever when you pull the pin. On the Tornado all you have is a pin, and you can attach it to your vest so it doesn’t get lost.

A few more things of note, there are 2 settings for fuse timing, 1.5 and 3 seconds.  They are both pretty accurate so you can set it to what you like and still be able to know when to rush in.  The last big bonus, especially of idiots like me, it the instructions are engraved on the grenade itself.  Not that this thing is hard to operate but it does take a few steps, in a certain order, to fill and reset the thing.  It sure helps having the correct order at your fingertips.

Now for the tests:

The first was in my garage...and let’s just say no corner was safe from the rain of plastic death (20'x25' room). BB's bounced off the walls and ceiling and as far as I could tell would have "killed" anything in the room. Taking into account most rooms in CQB are garage size or smaller, it makes it an awesome tool for room clearing.

My second test was outside in the back yard.   I gave it a good toss while I stood on my deck (the deck is about 3 feet off the ground) and the grenade landed about 20' away. When it went off a few seconds later, I was actually hit by one of the BB's.  I would consider that more of a lucky hit and say the effective 100% kill range is a 10' radius from the spot it explodes.  Even with it being outside there was a good dispersion pattern, although nowhere near as good as indoors.  My grass is moderately high (6-7 inches tall), and in need of a mow, so it did stop about 40-50 BB's right at the grenade.  I can see how this would make it pretty ineffective in tall grass unless you used the air-burst as described in the 4th video on the Airsoft Innovations site.

All in all I’m happy with the purchase so far, but only in-game testing will prove the real worth.  I’m tempted to paint it a brighter color, like blue or yellow, rather than keep it black.  I’m afraid I might loose it out on the field one day and I would kick myself. $100 is a lot of money to be lost in the weeds…

The final word:

On the positive side they are light, small and easy to use. On the negative they are not as effective outdoors and a bit pricey.  The bottom line is: If you have the money and want the latest, go for it!