Update 3/26/2015
PerfPRO announced last week that they now have power meter control over the Kickr built into their latest public beta download. You can find the beta download at this linkhttps://perfprostudio.com/Download.aspx
It seems like the only viable option at this time is in PerfPro.
If you want power meter control right now for Kickr ERG my thought is Get PerfPro.
Update 4/1/2015
TrainerRoad has the option available now and can be downloaded to a PC or Mac. I will give it a try this evening. A couple have stated that it works well.PC
https://www.dropbox.com/s/sg6yp9xnq8nwmgc/TrainerRoad.2.6.998.exe?dl=0
Mac
https://www.dropbox.com/s/fk4qsljghyr1oul/TrainerRoad.2.6.33.dmg?dl=0
The image below is a 20 minute interval segment comparing the Quarq data recorded on a Garmin Edge (yellow) and the data recorded in TrainerRoad (red) with the Quarq controlling the Kickr in ERG mode. All metrics totals for the workout session were the same at the end.
What is the solution for those who have either a hub based power meter or no power meter? I am not really sure and I have not heard or seen any discussion from Wahoo on how to improve the Kickr.
The Kickr is a pretty good trainer for wireless connection and for workout control from a program like TrainerRoad, PerfPro or others. It has a great feel and is of a good build quality structurally speaking. I am not an official reviewer that has thoroughly tested the data other than my own training data, which was about 15+ watts too high compared to two Quarqs and my Powertap G3 is within 4 watts of the Quarqs. I am confident when comparing my data that the Kickr's wattage was not correct and in my opinion not in an acceptable percentage range to those power meters. There have been a multitude of Kickr users that had the same experience with various brands of power meters being about 20 watts different. In a few rare cases some Kickrs have been below, but most have reported too high. There have been a few report that the Kickr was right on the money with the power meter from the start. So it seems to be a bit all over the place and I would feel it would be bad on my part to make good comments about a trainer and leave out something that a potential buyer regret later.
Thanks to PerfPro and TrainerRoad for stepping up to provide a means for those using power meters (non hub based meters) to control the Kickr and record the power meter data for historical training records.
Update 4/8/15
Wahoo announces on Slowtwitch a new beta firmware release.Here is the post. http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=5500153#5500153
A public firmware will be released soon.
Update 2/5/16
Here are a few screen shots from an active recovery session last night using the combination of the Kickr (latest Wahoo firmware update v1.4.39), Quarq ELSA, PerfPro (latest edition using the power meter control option). I've had about a 15 watt difference between my power meters and the Kickr for the total training session since purchase and it is still about the same, but it does seem that the application and firmware updates have improved the overall feel of the Kickr. It seems be a little less erratic in power meter control than previously.
The above image reflects the difference between the Kickr (purple) and the Quarq (blue) although it just happened that the point I did the screen shot shows a very close match. It is better to look at the overall power average in the Power Statistics.