FPS? Not a lot, I think around 200, but they have no flight stability, so the BBs just come out fast and lose mojo. It's an AOE thing. If a tornado lands in heavy grass or brush, the surroundings can absorb thing impact making it "meh". People are starting to swear by the Cyclones.
Here's what you need to know about grenades; mostly they are used as room clearers, because tossing them into the brush means really hard to find. And they are more effective on a hard surface. They are also the most commonly stolen item, because once you throw it you must then go get it right away. Some idiots get frustrtated and toss your grenade off into the wild blue yonder once it takes them out, then pretend they have no idea where it is. So basically, it's toss and then collect.
Thunder Bs are getting banned a lot of places due to the decibel level and potential shrapnel from them going off. I've never been bothered by one, but insurance and all that I guess. They're fun as hell though, and yes you can carefully load them with stuff, but they have no consistent regulation of pressure, so any and all injuries would be on you.
I have a timed tornado with a spoon kit and find maybe once a day where it's really feasible to use it. If I was playing more indoor I'd think of carrying more and using it more.
ďREALITY IS LIKE A STONE. TO MANY ITíS HARD AND COLD, THEY CANíT HUG IT OR EAT IT, IT ONLY FRUSTERATES THEM AND DOESNíT DO THEM MUCH GOOD. TO OTHERS ITíS STRONG AND DEPENDABLE, YOU CAN BUILD WITH IT, BUILD UPON IT, OR WORK WITH IT, ALSO USE IT TO SMASH PEOPLE IN THE FACE.Ē