So I had a couple requests for a write up on the differences of mesh and sculpty... as many people do not seem to be aware!
Both mesh and sculpted prims are made in external editors such as Blender or Autodesk Maya - there is free and paid programs to do so. However, that is about where their similarities end.
In terms of what they ARE...
Mesh are actual objects used in the professional world.... Objects you see in other games are a type of mesh. The ones we use to import to SL must be .DAE Collada... a specific type of format. I have to use a converter to get them to work right in SL.
Meshes can very in size, polygon/triangle count, and are mapped and textured externally so that textures fit properly. You must individually adjust each face (the area between each polygon, or if in wireframe... the spots between the wire meshes) onto a texture, it is not mostly automatic like sculpties.
The benefit this creates for mesh is that you're able to virtually get rid of what I call "Pinchy" ends... Where the textures bunch up at each end and generally look unpleasant. It also allows you to put multiple textures onto one prim... so instead of using 1 prim for the water, 1 prim for the bucket, 1 prim for the metal part, 1 prim for the handle... etc... You can use different "faces" like on a normal prim... or "Materials" in terms of what they call it in 3D objects to create the same effect. It is a great prim saver for a lot of things.
However, mesh does SCALE in terms of prims whereas sculpties currently do not. There is talk of changing that, but it has not been implemented and no plans are made. A mesh prim which is only 1 prim at 1x1x1 size, could increase in prim count dramatically by scaling it just a few % up - so size is very important. It is why I usually don't sell my items mod, I am just not ready for the ignorant to accuse me of lying and all sorts when my furniture is resized and goes up in prims.
Another thing that has effect is the size of textures used - your prim count could increase if you use all 1024 instead of 512 or smaller - so that is another factor to take in. A major one though that I struggle with often is the script count... It's a little biased, even a basic non laggy script will cause the prim count to go up significantly, sometimes doubling or tripling prim costs of an object (if unlucky.)
Mainly I try to avoid large textures and scripting for this reason, sometimes that could cause issue such in texture animated prims which stop animating if you shift copy - but I am willing to help that.. I really try to take advantage of the low polygon=low prim features that mesh brings to the table.
It will 99% of time look better than sculpts, and for smaller items at least, be much more prim efficient. It is a shame that it scales up so that at larger sizes it might seem more efficient to use sculpties... but people must also know that sculpties in general are laggy! You have to load an extra texture for them, their bounding boxes are iffy at best, they can only use one texture, and tend to not look nearly as good. Plus, all the extra vertices people use for sculpties means that they'll be a lot harder to render than almost any mesh on the grid today!
Overall, mesh is definitely my future. I understand people will continue to use sculpties, but for me personally, I'll stick with mesh. The UV wrapping process may be painful at times (takes a lot of time) and I am still new and slow with working with it, but I feel it is worth it. I want to be the very best at low prim, quality rustic furniture. Some day I'll have as many products as the rest, but for now I am very content with what we have.