The Grasshopper gets hot, but it doesn't take much to deal with, if that's a problem. If stealth is a priority the MFLB stem does an amazing job in a tiny form. It fits into the silicone mouthpiece, which also does a reasonable job for medium usage. Really though, it only needs to be cooled down if it's running hot or if huge smooth hits are desired. It can be dialled back in temp, but it is a direct draw device. It is simple to deal with in that regard and actually makes one of the best whip vaporisers I've tried. Totally portable too, and stealthy. It doesn't include a vape maze like a crafty/mighty but nothing is stopping anyone from adding one if they want, and it doesn't need to be big.
Often times I've shared my GH with smokers and they've preferred to use it direct instead of paired with the bubbler I was using anyway. By design it's going to get hot if you dial it up, but it's not going to burn you unless you really try, which is quite hard to do. All portable vapes have a high temp oven, near your face there is no mistake, it needs to be cooled down. You can take your dimpled glass cooling 510 vape mouth piece and plug it on your hopper.
In my opinion the GH is by far the best choice for a stealthy on-demand vape. 510 vapes are the only other way to go for flower and in my experience, it's a step down compared to a working hopper. In terms of ease of use, stealth and effect, power efficiency, the hopper takes the cake.
Battery life is about half a gram or less. Vaping on the go is a bit different to seshing on the go. You can take a lot of kit to use with the GH if you please, but the batteries are tiny so maybe taking a small pouch of them for a full day of exploring is a good choice, but it isn't required for a night out or trip to the shops, a movie, a meal out, whatever. The hopper and a single chamber might be enough. It's quite a potent little thing. People with no tolerance are amazing to see after a tiny hit off the hopper. Such red eyes don't lie.
If you already have a collection of reputable equipment you're only missing out by avoiding the grasshopper, especially if you want a stealthy ultra portable vape (because it's the only one).