I test my EAs on multiple brokers (FXDD, IBFX, Alpari) I used toused MIG as well but as everyone here seems to already be aware of their DEMO kinda sucks. For me MIG demo always seems to run for about a day or so and then dies. FXDD demo has a very solid feel. I like their demo but the backtester does funky things when you put it on visual mode. For backtesting I tend to use IBFXs metatrader. So far so good. Alpari is there as well for the sake of having an additional point of view from a European broker.
Now. You mention that you downloaded metatrader from the metaquotes site and the only demo option was MIG. I had the same thing happen. But i noticed that if I go to the other brokers website that I want to demo with. Alpari, FXDD, etc.. They all offer a free MT4 download. well its not 100% the same MT4. Its a branded MT4 so if you want other options in brokers just go to their website and download/install their MT4. you will need to install to a different directory each time but you can have as many as you want. Hope this helps.
Now. You mention that you downloaded metatrader from the metaquotes site and the only demo option was MIG. I had the same thing happen. But i noticed that if I go to the other brokers website that I want to demo with. Alpari, FXDD, etc.. They all offer a free MT4 download. well its not 100% the same MT4. Its a branded MT4 so if you want other options in brokers just go to their website and download/install their MT4. you will need to install to a different directory each time but you can have as many as you want. Hope this helps.