The more I use MGIV the more I've grown to like it as my all around paper. I can achieve wonderful cool neutral prints with selenium, beautiful split tones with sepia/selenium, and nice brownish sepia tones over the entire tonal range by indirect polysulfide toning (similar look to direct polysulfide toning on MGWT).
One thing I haven't messed with yet is trying to persuade MGIV to split tone in selenium like MGWT. I heard it's possible with redevelopers, but I have yet to try! MGWT is beautiful split toned in selenium and direct toned in polysulfide, but for everything else I prefer MGIV