How do you rate it compared to the rest? Is the battery user replaceable?
So put in some time with the new kid, and I got some impressions.
First question- how do I rate it compared to the rest?
I don't.
What I mean is, all of these get used for different things, so I don't really compare them against each other. Here's why:
The dynacup has stealth and a pair of 18650s going for it. I've taken this thing to my kids soccer practice, and never got a weird look. At worst it looks like I'm sucking Starbucks out of a metal straw. We also use an ArGo as a session vape, and since it uses the same batteries, they make a great pair to travel with because it's only one charger and 4 batteries we rotate. Always ready to go, and doesn't draw attention.
The OG VHB is my wife's weapon of choice. It doesn't really leave the house, but it goes all over with her. Watching TV on the couch, the garage, the yard, the kitchen, it's always close by and the battery life is fantastic and it's a great size.
The VHB Carbon is my favorite for around the home, too. Same as with hers, it goes in the garage with me, out in the yard, watching sports, and the battery life on it is an absolute MONSTER. I've got it tuned to where I can respect the click and not even have to think about it. This thing is the reason I stopped using my Caldron. Not that the Caldron is bad; it's not. It's just mains powered, and I hate having to unplug it, take it somewhere else, plug in, etc. It wasn't a big deal at first, but after having the Carbon for a few weeks, I took the Caldron to my workspace, plugged it in on the bench under the shop light, and that's where it lives now. The Carbon is just more convenient, and the tuning means I don't have to worry about anything when clicking.
The one that is most similar in size and use is the Flite. Both of these have considerably shorter battery life, and are also much smaller in size. As a result, these are the ones that are being selected when we're going out and about, and size/portability is the most important quality we need. So if we go for a hike in the woods, a day at the beach, some sort of social function, maybe an overnight.... these are the ones we're grabbing. Because all you need is one of the little guys, and your stash with the dynavap and you're all set. They're both consistent, tunable, and are really convenient at what they do. You just won't be able to go for long without having to charge them again. To that end, while the fit and finish of the Flite is amazing, I also appreciate the lighter weight and the convenience of the USB C charging on the VHB. It means I don't have to pack a proprietary charger if it does go somewhere with me for more than a day or two, and I can just use my phone charger.
As far as the battery being user replaceable; I don't know. I've not attempted to open any of the VHB units, as I've no need or desire to. Doesn't seem difficult, as there's 4 small Phillips head screws on the boxes keeping them shut. Might want to send the maker a note to ask about that. He's very friendly, and seems to know his stuff.
Having said all that; I find the VHB to be every bit as good an IH as the Flite is at the job. I don't think I'd pick one over the other, but I would definitely require at least one of them in my collection, for the specific advantage of portability and light use.
For other jobs, there's the other IHs.
TL;DR:
It's excellent and offering VHB Carbon performance in a Flite sized package, but with much reduced clicks due to battery size. Might not be best at Daily Driver Duties depending on your usage. Light users might never know the difference and it could check all the boxes for you if that's you.