Well, it's a matter of size with those two products. If you're built on the smaller side or like really tight orifices, then Sex in a Can. If not, then Fleshlight.
My hubby is average size and he loves his sex in a can version compared to his Fleshlight. He has the oral sex in a can he loves the ripples and ridges, and his Fleshlight is the nipple alley pirate version. If your man is on the longer or bigger side of average side then he would probably want a Fleshlight unless he wants it tighter. The cans are a great way to try out different textures for the price.