The new Phoenix viewer 1.6.0 is out. It is an optional update.
I can tell you that (for myself at least) it is much faster than the new SL viewer in terms of rezzing in and did not cause any lag once my textures loaded.
These antique musical instruments are by Mikki Miles and are Mesh. I just photographed them. They are amazingly detailed.
To download the new Phoenix viewer (note this is an optional upgrade and if your computer is older or if you have problems operating at high graphics you might want to revert back to the original viewer if your environment is too lagging):