Will unity performance improve in natty or remain slow?
There are some apps developed by canonical that are way too slow. This are USC and Unity. Unity in 10.10 is insanely slow (compared to GNOME which isn't actually a very fast DE) and totally unusable for a netbook (i'ts funny because its targeted for netbooks usage)
Will this get as good as GNOME in natty, or remain the same?
Solution 1:
Until now Unity has used the Mutter window manager, which is the next generation of GNOME's Metacity and incorporates Clutter. However this has shown itself to have mixed hardware support - while it works fine on some machines, it is (almost) unusable on others.
However Canonical has already ported Unity to Compiz, which has been the default window manager in Ubuntu for the last three years. This should lead to far better performance and hardware support - if you current machine can run Visual Effects (enabled in System->Preferences->Appearance->Visual Effects) then the new version of Unity should run fine.
Solution 2:
Unity will be ported to Compiz for 11.04, which should help performance quite a bit. Also, according to Rick Spencer's blog, Canonical plans to do quite a bit of other performance work this cycle.