regarding to the location of the key, volume, and usage?
And what would you preffer, the button c hole or the upper c key ?
Thanks!!!
The two Fs each have their uses and supporters. For example, a short F is hard to use when going from D to Fnat - there a long F works better. There are other times it’s easier to use the short F. I think having any F key is better than none, and two are ideal.
The Cnat key is, IMHO, next to worthless. While it gives a perfectly in tune note, I find it the least logical key to use and prefer the sound of the cross fingered Cnat notes. Despite that, I will use it for the high C when I need to hold that note (which is really a rare event). A Cnat hole would be my preference over a key, but I’d probably still not use it very often and would prefer to save the money to buy some stout or bitter. 
Eric
What??? Wow man, that’s amazing - aside from the tuning issue, I find whacking the the cnat key far quicker and easier than the going for the for the cross fingered equivalents. And on slow tunes, where tuning/ intonation is really noticable, the key is sooo much better. I guess a hole would be okay too (on slow tunes), but at speed, I love the key in most circumstances.
Loren
Just as you cannot smoothly move from F-natural to D with the short F key, you cannot move from F-natural to A-flat with the long F key. So both are important.
As to the C-natural key, I find it easy to use, and handy, but I do agree that most flutes have perfectly fine, easy fingerings for C-natural. The key is nice to have but not necessary.
On some flutes, second octave c-sharp is very badly flat; venting the C-natural key with this note will bring it up to pitch, which makes this key pretty important, especially on slower pieces.
-James
I think only evil flute makers really like the Cnat so much…
Seriously though, OXO XXX has always been as in tune as the key for slow pieces on the flutes I’ve played, and I think the pure Cnat clashes with lots of trad tunes. I much prefer either the above, the classic OXX OOO or even OXO OOO for ITM.
I think I use the Cnat key for the high Cnat on only maybe, um, two tunes. On an M&E, I’d pay for the Cnat - on any other flute, they tend to cost between 18 to 31 six packs of good/real beer or ale.
Eric
Muuuwwaaaaa haaa haaa haaaaaaa!!! 
You crack me up Eric. I guess it all comes down to how you hear, and play things: I used to think the cross fingered cnat, with it’s slightly out of tuneness sounded good, but after getting a keyed flute and playing Laurence Nugent’s version of Paddy Fahey’s both ways(Keyed and crossfingered) I was converted - now I simply can’t stand the sound of *(slower) tunes played with an even slightly out of tune cnat. But then I’m sure there will be any number of players who will pipe up to say they can play a perfectly in tune cross fingered cnat on their flutes, so as usual, it’s just a matter of me and my sucky playing 
Loren
I doubt your playing to be sucky…I simply think it a matter of taste. I hadn’t had a keyed Cnat in about 2 years, but now that I have a flute with a Cnat key, well, my opinion of them didn’t change.
I’m probably still influenced by about 14 years of serious saxophone playing (although it’s been 20 years since I last touched one…man, am I getting old or what?). The RH first finger shouldn’t be used to create a note using only LH finger 1…just seems unnatural.
Eric
You never used the B# key (side C) on sax? It’s more in-tune than the other C. 
I have the short F key, and miss the long for some passages.
As for the C key, cross fingering for quick pace. However, I find it useful for those well-tuned long C’s natural and some sliding effects (make me think of Stor mo Chroi or Lovely sweets banks of the Moy, beautiful tunes are they are with C natural recurrency.)
Let’s be honest…I love those long keys…aren’t they smart?