The build quality has improved over the older D-Lite with the main improvement in the flash head clamp to your light stand.  The Elinchrom D-Lite 4 it retains the 1/10 stop power control provides very quick recycle times, as well as having very consistent colour output which is important to reduce your time in Photoshop. 

The new D-Lite 4 it adds the Skyport wireless trigger system to the heads, and includes a Skyport Eco transmitter which will trigger the heads, but isn't able to control light output like the full Skyport Wireless trigger.  I had no problems syncing at 1/250 sec on my Canon 50D and the Skyport system never missed.  Range was no problem in my studio although I haven't tested outdoors yet.

This new D-Lite it also adds an automatic temperature controlled fan and a small reflector.  The softboxes are now the same size (66 x 66cm) whereas the older kit had a large and medium softbox (66 x 66cm and 55 x 55 cm).  More on the automatic temperature controlled fan later.

The new D-Lite 4 it set also has a proportional modeling light.  So the intensity of the modeling light changes with the power the flash head is set to which is great.  It just makes everything easier to get right!

Like before the Elinchrom D-Lite 4 it has an eye-sense technology that can automatically trigger from your camera flash or other studio lights.  These can be very easily set for cameras with pre-flash as well.  I had no problem using the automatic setting with my Canon Speedlites.

Overall my impression is very good of the system, Elinchrom lights have great output consistency and the build of the lights is pretty good.  The carrying case for the flash heads was a lot better than I expected and fairly well padded.  The softboxes like before aren't the easiest things to disassemble and reassemble but provide a fairly decent light quality.

The only problem so far seems to be a design flaw.  With the heads tilted down, maybe say greater than a 45 degree angle they overheat very easily.  Even with just the modeling light on.  The lights will throw an E8 Error code and power down for a few seconds.  They don't seem to have this problem when level even on full blast and shooting.  I believe this is a design flaw because I can duplicate the problem on both heads, and the fan doesn't always come on before the E8 fan control error.  Meaning the lights are over heating and the fan isn't automatically cycled on. 

Updated (April 1 2010): No, not an April fools joke.  Vistek didn't seemas serious about looking into this as when I first spoke to them on the phone. So I decided to contact Elinchrom in Europe directly. After all it seems a very easy problem to duplicate. 

Use the below directions at your own risk.  Failure or damage blah blah to your equipment is not my fault, you do this on your own etc.

This is what they suggested:

Dear Mike,
Thanks for your message and the exact description.
It helped us very much to understand and simulate the E8 ERROR MESSAGE.

There is no hardware fault, it is the software configuration of the D-Lite-it unit.

I have attached a file, which shows, how to configure the unit correctly. Please read the PDF carefully..

   1. Pls. look at paragraph 7.1, it shows the unit sub menu configurations.
   2. The parameter which must be changed you find in the last row: FAN CONTROL / F.0_F.1
   3. Please do not change any other values, just only the Fan Control.
   4. The new value must be F.0 instead of F.1!!!
   5. Now go to paragraph 7.2 and read how to ENTER this sub menu
   6. To toggle to the “Fan Control” Menu you need to press the Modelling Light button 4x
   7. Change Value from F.1 to F.0
   8. “Save” and “Leave” the unit configuration as we describe in the PDF.

 

I've attached the PDF they sent me.  Basically it seems fan control tries to toggle the fan between temperature ranges 45-55 celcius and may or may not work properly depending on your usage and definition.  If it is not regulating properly, it seems the E8 gets thrown.  By disabling fan control it seems like the fan kicks in at a higher temp and E8 doesn't get thrown at 55.

At first I was skeptical.  I tried it out side by side.  One with the value changed as above, one without.  The D-Lite it with the value set to F0 does indeed seem to have the fan turn on automatically and shut off still, but no E8 is thrown.  I'll have to test more tonight as I don't have time right now.  But for others having the same problem this seems like a better solution as changing modeling light bulbs seems a band aid at best.

Just to be clear, the fan will still stay off, and come on when needed.  I think it just comes on a little later.

Elinchrom D-Lite it fan control service manual pages.