Anybody running one? Do they help with throttle response and power or is this a supercharger in a bottle?

I heard it doesn't help but can't really tell you why

More of a gimmick. They are supposed to help with off line the acceleration by increasing the volume of the crankcase allowing it to have more fuel & air, sort of like a storage place, but dont really seem to make any difference.

they used to be handy on SOME engines back in the day for cheap engines like TOKI, Fantom, and so on.

Now, most engine manufacturers design engines BETTER so they dont need boost bottles.

ok i have gathered these boost bottles dont do much for increasing power, just they give you better throttle response, but what is the go with the boost bottles with the Nos Canisters attached? Would this give me better increased power? or will it just simple damage my engine? I just bought a 49cc rc boat and want to build it up to its full potential but i dont want to damage it engine wise, all input would be appreciated......

I'd say with 49cc you'd be wasting your time with those MIP bottles, or Nos kits or whatever.
But good exhaust, carbie and porting job (by a pro) with the right prop and so on would probably yield a substantial performance gain