Sculpties are great!
What I like about them most is the abillity to make the smallest of prims using large bounding boxes (I'll explain those later). But when you have small prims, working or vieing from a distance you'll see they become blocky and lose their shape.
There's a way to fix this;

Believe it or not... this is a star. It's sculpted and yes it has fully rezzed. It's just at a distance.
Let's make it look better at this distance now.

If you don't already have the 'Advanced' menu hit CTRL+ALT+D in your SL Client and it'll magically appear. Click through Advanced and select 'Debug Settings'.

This little window will appear. Inside the text box put in 'RenderVolumeLODFactor'. The Value box will be set to 2.000 as a default. Put this to a value of 4.000.
(or if you're really brave and confident your connection/hardware won't suffer put it up to 8.000)

Close the Debug Settings box and you'll hopefully instantly notice the difference. The star's now showing as a star rather than a block at the same distance.

Of course some small sculpties look fine from a distance, other's don't. But changing the RenderVolume really helps us when building those small details and I hope it helps you too.