IDE: QtOctave
Toolboxes: Exceeds those of Matlab (
http://octave.sourceforge.net/packages.php)
Speed: On par or better than Matlab generally, unless you use compile your Matlab with MEX (but then, Octave interfaces with C and Fortran for even more speedup).
Python is better generally than matlab/octave, and R I view as roughly on par.
*Source: 7 year veteran, octave and matlab user, python lover