Correct.
Great for that, not so great for versatile lab use.
Can't agree. You can't change the temp, but you can change the tips. They have some larger knife tips for soldering large parts (TO263, etc.), and they have some tiny bent conical tips for debridging QFN pins.
A Metcal stand comes with a few holders for spare tips, and a thermally insulated rubber pad for quick changing.
After 5 years of use, I learned not the fiddle with temp even with conventional stations. My JBC and TS80 are all set to 330C and I seldom have to change that.
Versatility means the ability to easily adapt to changing requirements.
There are two aspects to every soldering iron in terms of flexibility:
1) The range of tips available
2) The ease to regulate and adjust temperature
Fixed temp irons
force you to do #1 in order to do #2, adjustable temperature irons do not.
The argument whether or not
you do or don't have to is not relevant to the discussion of flexibility. It's a demonstrable fact that adjustable temperature stations are more versatile than fixed temperature ones, you can't argue that.
If that flexibility isn't important to you, that's completely fine. As stated before, it can actually be an advantage in a production environment, but we aren't talking abut that when it comes to flexibility.