I traded MBT Demo on MT4 for a few days. First off I noticed that the leveraging or lot sizing was quite odd. Now I know why. After the first day, some open orders disappeared, then reappeared 2 days later. That was kinda fun! Then I had open orders that I couldnt close or modify, even funner!
At the time I ddnt know it was still in Beta because some potential clients gave me the demo account.

I've chatted with Ramon online chat several times. Hes the tech support guy for MT4. Very helpful and Im looking forward to opening an account with them if they ever get their MT4 Server into production.

As of last week (April 1) they could still not give me a go live date for MT4.