My main problem with actual tube lights is that you can't actually see the light, which is a big hassle.  If they made it's avatar an actual tube instead of the bulb avatar, then it might be useful.  There are some other issues with lights that I have in Carrara.  For instance, if you have a bulb which you want to have a glow sphere on, you don't have the aura option, but if you use the light sphere tool, the sphere completely ignored anything which might otherwise shadow it.  As an example, look at a simple old fashioned hanging lamp.  You create the lampshade which is attached to the ceiling by a cord of some kind.  Then you add the bulb and internal fixture.  Now most incandescant lamps have a subtle glow halo around them.  However, with the bulb you either have to forgo an actual light just to get the bulb to glow a bit with aura (which never looks natural for a lamp glow, or you need to add an actual light bulb.  Now this would work great except that when you add the light sphere, it even glows through the lamp cover on top as if it wasn't there.  They need to make a light sphere react to collission with an opaque object in the same way the actual light does.  And if your thinking why not use an anything glows, well, you should have the light sphere option with all types of lights but you don't.