Sony's tools support got a lot better after they bought SN in 2005, but it wasn't that long ago that you couldn't do things like source-level debugging on an SPU (I assume you can now). Compare that to something like Pix/remote source-level debugging, which the 360 has had since day 1, and the difference is quite clear.
SPU debugging has been available since at least 2007 going by archived email conversations I have on the topic, and I recall it working even before that.
Sony's tools stopped being annoying around 2007 and have been excellent the last few years. In some ways they surpass what's available on the Xbox 360 -- Tuner and GPAD are more flexible than PIX and the debugger isn't tied to the massive anchor that is Visual Studio.
