Hah! I agree, both of them have sucky websites.
First, I'll start with the Elk M1 Gold. It's basically a security system, but allows for Home Automation through the M1-XEP ethernet module and serial port expanders that can control Z-wave, X-10, Insteon, etc. It allows one to write automation rules that can control lights, thermostats, audio distribution (such as Russound) or general relay outputs for sprinkler systems or whatever else you choose to hook the relays up to. It's a perfect general purpose controller that would integrate very well with DomoTiga. And it's very modular, so you can add to the system as needed. Most of their information and documentation is available on their dealer site:
http://m1dealer.elkproducts.com/
An account on the dealer site is free, and they have documented all of their protocols for control and data gathering. In reality, you could probably do nearly 100% of all home automation functionality just with the ELK system. ElkRP is their software which is used to program the unit, but it doesn't have a lot in the way of monitoring. You probably wouldn't leave it open and running all the time. The ethernet expander has a Java interface that you could leave open, but I'm not very happy with it. Someone has make an iPhone app called eKeypad Plus which is awesome, but it obviously doesn't provide a central server type functionality for logging and creating external rules or control of other equipment. There are a lot of people with tons of experience with the Elk on the cocoontech.com forums, and likely plenty of people there that would be glad to help test DomoTiga with the Elk, including me.
Brultech's site seems to be down now. But if you click on the residential section from the front page, it will give you the general overview of the ECM 1240, which is the current model. The unit can connect via serial port, via an ethernet->serial bridge, or via Zigbee Pro->ethernet (which is what I'm using). There is a small python script that someone wrote that reads the data and inserts it in a database, displays it, and/or uploads it to Wattzon.com for graphing. You could get an idea of how the data is read by checking out the source code here:
https://bitbucket.org/kelvin/pyecm/src/
As far as power monitoring goes, Brultech was the cheapest option I could find that would monitor the main feed *AND* a bunch of other circuits. I have mine monitoring my main feed, air conditioner, and about 8 other circuits. The unit has 7 channels, but you can put multiple CT coils on a single input to add them together if you want. They start at $180, and go up to about $400 for the package that includes a ton of CTs, Zigbee transmitter, and Zigbee to ethernet router.
When their site comes back, you can see the overview for the 1240 here:
http://www.brultech.com/HomeEnergy/ecm1240intro.html
And somewhere, they have a page listing all of the 3rd party software that supports it.
One of the interesting things that I think you could do would be to use it to identify a "power signature" for every item in your house, even though you don't monitor them individually. This way, when DomoTiga saw a circuit increase by, say, 72.4 watts, it would know that you turned on a certain device, like a stereo.