I've had my VSG60A for about 8 hours now. Does what it says on the box. Signal Hound markets it as a 'vector signal generator,' which is what I currently need it to do, but in reality it appears to be a very competent general-purpose signal generator.
A CW signal at 100 MHz almost meets the HP 8662A perf limits:
Big two
so far. The only thing that's tripped me up is that if you connect an external 10 MHz reference, you have to restart the software. Otherwise the 'Ext Ref' button won't show up at all... and if you don't press that button, some artifacts will result.
Of course, being effectively a software-defined radio transmitter, it's not meant to compete with dedicated signal generators when it comes to specs like SFDR, absolute amplitude accuracy, or RF leakage at high attenuation levels. But my initial impression is that it's better than it has to be. They've done a good job on the basics, and you sure can't argue with the price.