obvious feature request !

> the ability to extend the range of the instrument beyond the original. Why are there a limit to this ? Let's have a mastertune that goes +- 2 octaves

I think this is already supported in the models.  As far as I'm aware they already push this as far as is practical, something to do with the limits of the human ear to detect frequencies (but I'm happy to be corrected on this).

> the ability to morph two different models, say, piano and harp

> a sub tone generator, not necessarily complicated, but enough to beef up the sound of, say, a glockenspiel with a sine tone underneath

> a few more efx slots: as we've got 10 efx models, why can't we use more at a time then ?

All three of these would be better achieved using a DAW.  It's not really practical for Pianoteq to extend it's features into this area as, IMO, it would divert the resources available for development into areas already handled by other packages.

> the ability to morph two different models, say, piano and harp

"morph" may mean more to you that blend (which is my interpretation of what you mean), but if so you need to be more explicit about what you want to do.  Again, however, I'd suggest that for most purposes feeding Pianoteq VST outputs to a DAW and doing additional processing there is probably the most powerful way to manipulate sound than anything Pianoteq could provide.

I would vote for allowing notes way beyond the instrument octave bounds.  It may end up sounding totally weird but I'd rather have weird notes than absolute silence.  Maybe make those keys a different color so you know you hit something weird.

If there's already a way to extend the range of the instruments, then I'd be most grateful to learn how to do it. Anybody ?

more fx slots: I don't know about you, but Pianoteq absorbs nearly no processor power on my machines - why not have more of a good thing then ? If you can have these options in Kontakt, you know why it's great to have fx as a part of your preset sounds rather than something you set up in your DAW. Not least if you perform live...

a sub tone generator: not a processor demanding thing. If you've ever fumbled with synths, you know how much this can do to a sound without you actually 'hearing' it.

a way to morph models: what I meant was in fact 'blending'. As you know, most instruments already consist of more than one sound: take a banjo (no jokes here !), timpani etc. You've got a percussive sound blended with a tonal one. It makes sense.

Modartt are doing a great job - but they can go further and the tech involved here is not something exotic. AAS are already doing it, so are Wallander instruments. Modelling is the real alternative to sampling. Why not push it further ?

No, I don't believe things like these are better solved in a DAW: a lot of other software manufacturers are doing this already, giving us instruments with more options out of the box. What I may be suggesting, may be a sort of 'Pianoteq+', add ons that you can purchase, leaving the original instrument for those who don't need stuff like this.

The iPhone was a result of somebody looking for new ways. So was Pianoteq. Keep it up then !

My 5 cents :-)