Only if your cars require RON higher than 97.
Just he same like asking if RON97 is good or not, it's good only for cars requiring RON higher than 95.

Is it really ron100 or actually still ron97, just the floor already painted 100?

Hmm not bad, not as expensive as early rumors.

No need to make things more complicated.
An engine which is already optimized/tuned to produce the best performance for example at RON97 will not yield any additional benefit when running higher RON than 97, so no need to waste your money buying RON100, just as simple as that.
If an engine is tuned to perform the best at RON100 then it would not give it's best by using just RON97 and therefore just go ahead and try the RON100 as it should give better performance.
If an engine is say optimized for RON98 then what you can do is mix RON100 with either 95 or 97 using just simple ratio to get RON98, then that should give you the best performance already, no need to fill up full with RON100.

Still the same, 2.80/ltr.