Abused question, I fear, but let me sketch my experience about this.
I tried 2 toons on PTS, both NB, one stam the other mag, builded Alcast wise. Now, the mag was clearly superior in my hands, and the same happened using the 25lvl.
So, I started a live bret magblade, putting aside my dunmer stamblade. My opinion? Raising a magblade is a real PITA, especially if you are accustomed to sorc and/or plar: decent sustain, but slack DPS, and the really good skills are gotten fairly late (I'm thinking of Merciless Resolve, Siphoning Attacks, but also the Shade, that is a good complement). When stam, you have good DW and Bow early skills to use, nothing comparable for the staff