it seems that Symmetry is not really achievable especially when you try to work with less vertices?
Symmetry is easily achievable in Sculptris for example assuming that the low poly underlying mesh is symmetrical. Is your low poly mesh symmetrical ?
And we can say goodbay to sculptris too! 
yeah I never had those Symmetry Problems inside of Sculptris but Dyntopo is inside of Blender 
the standard cube was used also the Symmetry Mirror X was activated.
the first brush strokes it will work fine but when there are more changes in the geometry, it will start to be asymetrical.
edit ;
even in the early stages Dyntopo gives you the ability to split the sculpt into two meshes
which can hardly be made in Sculptris.
- if you want to use the Grab funtion you could use the Snake hook.
it might not be the best solution but better than making your object a complete mess
Right now no attempt is made to keep the topology symmetrical. Topological symmetry is certainly a highly desirable feature; it needs some thought though as to how it can be implemented.
ahh thanks for the clarification.
Is there an option to donate to this project? 
(it feels great to doodle in Blender again)
You can make donations to sculpting development here: https://www.wepay.com/donations/nicholasbishop.net
There’s also the general Blender Development Fund: http://www.blender.org/blenderorg/blender-foundation/development-fund/
wepay made some problems so I gave money to the Blender foundation.
sculptris symettry is really dirty… it’s more like using the mirror modifier with clamp in blender then actual sym.
Yes, true, Michael W.
I get a lot of nasty artifacts at the sym. seam in Sculptris that takes much fiddling with the reduction brush to get rid of them.
Sculptris symmetry means, mirror and weld.
The worst is that you can’t leave parts stay asymmetrical. Terrible limitation.
You may also noticed that working on SC symmetry boosts performance. Right?
Zbrush has a mirror and weld option too. Similar artifacts but here we can remesh-dynamesh after.
Mirror and weld is a very useful tool though. In sculptris for instance, can be used for making topological holes.
Have a look on this simple tutorial.
Can someone tell me why Unlimited clay is dead? What happens?
The developer is in Cuba without an internet connection.
UC is dead because its deveoper started working for a company responsible for 3D Coat (as far as I’m concerned). In other words he doesn’t have time for volunteer work anymore.
I believe the earlier comment is correct – Farsthary finished his work with 3D Coat and is back in Cuba without internet.
apparently he is back in Cuba and he is not working on 3DCoat anymore
Hi Nicholas did you know of this ?
Paper
http://liris.cnrs.fr/publis/?id=5391
Did email you also but as my mail may end up in a spam filter I post it also here
@Nicholas - Good to see a fellow South Carolina Blenderhead on the forum I didn’t think you guys existed.
That is exactly what he is basing his code from.
Aha, now I feel stupid. But then again this whole thing from a technical POV is way above my head.