Since you're talking about VL stuff - allow me to join you.

Well, the VL150 has a few improvements from the VL70-m. The 64 user memories on the VL70-m never worked properly, 'cause they couldn't store all the parameters. If you edited a sound on your computer and then tryed to store it in the user bank (not the 6 way memory buffer) it always ended up screwing up the sound.
The VL150 plug-in doesn't have that problem.
If you're looking for leads, Yamaha made an "analog editor" for the VL70-m. It should work for the VL150 plug-in.
It is very easy to use (unlike the "expert editor" ).

I was able to get some VERY convincing saxes, flutes and even violins using my WX controller. If you want to get a convincing sax using a keyboard (using a BC) play pentatonic mode and avoid pitch bending too much.
As for guitars... Well AJ's right, lack of polyphony is an issue.
They should've made the VL70-m and VL150 at least duo-phonic (like the original VL-1).
But if you're looking for killer bases, interesting synth leads, winds and violins
- VL 150 plug-in is a thing to go for.

-ED-