I am a NS Dealer, and have done quite a few installs with the Digi line, as well as a few Panorama (for video). I designed and sold Crestron systems for another company previously, along with Elan. I would put performance of the NS Digi system on par with Crestron on most points. They are slightly limited on overall options compared to Crestron, as they don't manufacture their own lighting control, XM module, thermostats, and a few other basic things.
As was mentioned above, however, is that you can program a complete NS system in a day, or less, depending on its size. You don't need a Doctorate in any programming languages to set up a core system. NS is working on an update, or actually a rewrite, to their programming suite, that will simplify writing your own drivers for advanced integration and control.
Take a look at the recent posts on NS and Digi under the Custom Installers section for more info, or PM me with any questions.
They might not yet have 2k employees, but they still do the job. I haven't read anything about them that compares to what people say about Control4 or some of the other "systems".
Also look at my last install,
[Link: remotecentral.com] .
That should give you an idea of one of the homes I am comfortable installing NS in. I start up the final phase of a job in a 15k sq. foot home next week.
This stuff works.