I have sold both & feel C4 is a better solution:
Elan has been very very slow to respond to the needs of the consumer in the touch screen/home automation market. Many co's have passed them by & I guess the reason for this is that they did not want to alienate their legacy product. Elan purchased Home Logic a few yrs ago in hopes to regain its share of the market. Unfortunately they have done very little to integrate the technologies of Home Logic into the Elan line.
Then more recently Linear purchased Elan, Niles, & Xantech with the same vision.
In my opinion Elan does not have a clearly defined, integrated, and networked based product offering for whole house automation, lighting, security and HVAC control customers.
In my opinion these are the negatives of an Elan system:
(it has been a yr since I sold there product so I am not sure how much has changed but from what I have heard I believe evrything listed below is still true)
-#1 by far. The touch screen overlay & programming templates. You can only use the templates they provide. You can't move around buttons or customize the touch screens. As a programmer I need to make the most of the real estate on the screen & tailor it to meet my client's needs. As far as the overlay goes in this age of technology it is unacceptable that I use this method. For ex: when switching to different security cameras I have to hit a certain part of the screen to move to the next camera or back to the home page with no buttons on the page? If I touch a certain portion of the screen say the right corner it moves to the next camera. What?
-Music sources: No Rhapsody, Pandora, or Internet Radio (yes they can be a little problematic sometimes but I love Pandora) And they don't require an antenna like an fm tuner for reception.
-There music hard drive system (ViaDJ) is old & outdated. Even though they added the Sunfire DVD/music server it's much more expensive than Control4's solutions.
-The graphics are old & outdated
-No wireless solutions for lighting, audio, & HVAC.
-Lighting control needs to be a separate system for ex using Lutron. This is because Elan does not provide 2 way feedback for lighting control. I tried using it in the past & was unhappy with the results.
-They wireless touch panels they offer (made by Nokia) were unreliable last time I tried programming one.
-Wireless lighting options (prefer Lutron over C4 nicer fit & finish) & wireless speaker pt product.
-Interfaces easily with home automation products providing 2 way feedback. And because many of the program drivers have been written already it minimizes programming time.
-Rhapsody & music/media hard drive system with a great interface at a reasonable price.
-Offers a much nicer remote solution for Home Theater or in a room where you have for ex: a TV, DVD player, & cable box & still want to automate your home.
-They have a iPhone/iTouch/iPad interface
Control 4 negatives:
-Need to offer more online music services like Pandora. There is a co who wrote a module for Sonos that I want to try. It doesn't offer cover art yet but it's in the works. This would allow you to integrate Pandora, internet radio, etc...
-Need more integration with HVAC & security. If this is an important need I would suggest Crestron or AMX.
-It is not as flexible as AMX or Crestron but it meets a price pt that the average consumer can afford.
I used to love Elan & it's hard to watch a co that helped me pay my bills for so many yrs head in the direction they have. I don't understand why they have not put much money into product development or new technologies over the last few yrs.
Good Luck let me know if I can answer any other questions.