[gtkmm] Qt converts?

[Staff <staff transportationimpact com>]

Are there any Gtkmm converts from Qt out there?  Although I like Qt, it is so 
darn expensive (even the annual maintenance fees $1000/seat for a dual 
Linux/Windows license and this will get real expensive as I hire some more 
programmers) and compiling is becoming so slow (ie about 15 mins on a 850mhz 
256ram machine).  But I have the following questions re Gtkmm:

1) how portable is it to windows?  Frankly our Qt code is virtually 100% 
compatible and our user base is virtually all windows - for now:)
2) Will it be faster in compiling?  I'm roughly observing that the extra moc 
compiling in Qt is taking 1/3-1/2 of the total compile time.  This savings 
would be significant since recompiling is done often.
3) Will it be a huge learning curve to switch?  Especially with a lot of 
graphics classes (I'm assuming that Canvas would be equivalent to QPainter).
4) Are the openGL classes working well?  We envision switching a lot of the 
drawing to openGL in the near future.
5) What IDE or Dialog editors are people using?  While many rave about 
KDevelop, I actually find that vers 3 is still pretty buggy.
6) How easy is it to cross-compile with MinGW?
7) It appears that Inkscape is using Gtkmm but that many of the other C++ 
Gnome apps (ie Abiword) don't - why not?
8) What would be the major advantage of Gtkmm over WxWindows?  

thks.
John