How Good Are Studio Instruments In Sonar (strings, brass etc)?

That's a loaded question.  They're as good as you perceive them to be.  Are they as good as you need them to be?  That's up to you.  I use them from time to time, but I wouldn't want them to be the only samples in my collection.

I've really started using the SI-Electric Piano pretty heavily, and will sometimes use the SI-Bass Guitar when i'm planning something out and a real bass isn't convenient.
Never used the drums or strings.
 
I've found that, like most synths, it's all in the programming.  A good programmer can make a mediocre synth great, but a bad programmer can't always do much regardless of the product used.

michael diemer
How Good Are Studio Instruments In Sonar (strings, brass etc)?

If you're comparing to the most advanced sample-libraries available... they're not going to stack up.

Thanks. Do they stack up to the Dimension Pro? I use a few sounds from that. If I got even one or two decent sound, that would be good.

I have used the electric piano and strings before as pad sounds.
 
Bob Bone
 

I believe they are culled from DP.  Please correct me if I'm wrong.
 

robert_e_bone
I have used the electric piano and strings before as pad sounds.
 
Bob Bone
 

Ditto.  I use them for lightweight, very realistic sounds that can be used quickly.  Depending the overall piece, you may or may not want to replace them later on.  Not the drums though.  I have a template for a basic EZD2 kit, so I always grab that one for drums.

robert_e_bone
I have used the electric piano and strings before as pad sounds.
 
Bob Bone
 

The strings are much better than I thought if you don't want realistic strings and sound like they are coming of a synth. They sit nice in a mix.  There are times I don't want real strings.