I'll throw in that I own the Hakko and have been EXTREMELY pleased with it. Being able to dial in to a specific temp (and more importantly, having it MAINTAIN that temp!) is highly important to me.
I bought a cheap Harbor Freight soldering iron (I think i paid $5 for it) and I discovered, VERY quickly, why it was only $5. It took forever to get it up to temp, and when it DID get hot enough, I could only use it for maybe 15-20 seconds before it cooled off and the solder wouldn't stay liquid.
Does this mean that what you’re considering isn’t a good one? Not at all. I don’t know anything about the TS100, so will have to defer to someone else. But I like the Hakko, it works great for all of my builds, and it doesn’t feel like an el cheapo Harbor Freight soldering iron that likely doubles as a wood burning pen.
I do like that the Hakko comes with a solid stand for the iron, so I don’t have to worry about accidentally setting it down and melting something, or catching something on fire, etc. whatever iron you get, make sure it’s got a decent stand, something that’s not easy to tap lightly and the iron tips over...