Beyond F#3, their lies a whole range of notes way beyond the normal range of this instruments standard written notation. What fingerings have you more experienced sax players discovered. For example 1&3(LH) and 1&3(RH)( +Bb side key) you can play either G above high F# or C4 depending on how you hit the harmonic.

There's a lot of fingerings posted on "the woodwind fingering guide".
http://www.wfg.woodwind.org/sax/index.html

Indeed. To be honest, I've got a value varied embouchure, and I can usually hit the note I'm looking for even with the wrong fingering, as I can slide it a tone in either direction. I find the easiest high note to play is A - played as a D without the first finger.
However, I can not (and never have been able to) play the G a semitone above F#3 - I find it absolutely impossible, although I can get the G# and all the notes above this.

David have you tried this fingering for high G3- Octave Key plus 1+3(RH) and 4+6(LH) and side Bb. I have discovered that using that fingering i can also lip up to C4.

Hmm - I'll try that in the morning.

The problem is, that with my new sax I'm having to get used to a rather different style of playing - it's a lot easier to get the hard notes out, but slightly harder to get the easy ones out - in short, it's far more balanced than any yamaha I have ever played, but I've dropped reed strength temporarily to get used to it, which means i have ot be careful not to try to play as hard as I normally do, else I overplay the reed.

In layman's terms, I'll probably hit the C4 straight off, and fail to get the G