@Horatio:-
I wasn't going to anticipate Neil's reply to using EAs (but I had an idea of his view of them). However, one thing that you can do in MT4 (if you are actually trading off it, and not just using it for the charts and indicators) is to have scripts to quickly get in and out of trades, and also to quickly modify trailing stops or take-profits, or close all trades ... that kind of thing.
I have only ever spread-bet, and as most of the SB firms don't/didn't support MT4, I'd had little occasion to trade from it in the past, except on demo, and as we know, demo can be a little misleading. In comparison to the relatively simple platforms of the usual spread-bet firms, trading off MT4 can seem a little clunky at first, e.g. setting stops and TPs can be a bit of a pain, especially if price is quoted to 5-decimal places (which SLM do for the majors and are extending it).
However, one can write (or find fairly easily & modify) scripts to do this, which one could activate via hotkeys - 1-click trading if one wants. Anyway, that is a line which I am investigating as a background activity. It's not like using an EA. The judgement on whether to trade and in which direction is entirely manually taken - it's just that when you do decide, you can act fast, if the market (and your time-scales) dictate it.