I've never used Finale, and got to Sibelius quite late...
An elderly colleague of mine - in her 80s now - uses Sibelius, and often seeks my help on it when she is stumped. I peer and peer, and eventually dispair :( Whereas I find that even the most obscure tasks in Finale have a clear and instructive "Help" screen for them. Tuplets are simplicity - you just set 'how many' and the note-duration, and you can enter your noteheads immediately... they engrave neatly-proportioned. I was putting in some 17ths last week - all quite straightforward. I agree that perhaps the instrument sounds (even with the new sound-palette in the latest release) are a bit parpy, and the dynamic gradations can be lumpy in marked crescendos - but these are things which only bother people who are working towards a 'virtual performance". Personally I'm using Finale as an arranger's tool, to score ensemble and orchestral parts, and print them out for performance by live musicians. (Part-printing is one of Finale's real strengths - extract and print in one operation). In the final analysis, I agree, Finale began as a jazzbo and band-master application, and its allegiances are still in those fields. I think I began using Finale mainly because it's the favoured programme in Russia, where I live - and everyone passes around their files and parts in that format.
The only main thing I have never achieved in Finale is creating non-mensural notation, without time-sigs or barlines (except where I wish to impose an editorial barline) - for example, for writing out plainchant with stemless noteheads (which I have to do, on occasion).