I have no connection with the companies that offer these EAs nor do I receive any compensation for recommendation or referrals. This is just my humble opinion about some grid trading strategies that I have used.
Grid trading is a reasonable trading strategy. You just need to fully understand the strategy and accept it's risk to reward factors. Grid strategies are no different than any other strategy. You can risk a small amount to try to make a small amount, or you can risk more to make more.
Can grid strategies blow the account? Of course! Almost any EA can blow an account, especially in extreme or wild market movements. Just take that into consideration when using these strategies. My approach with grid strategies has been to start with a small account with an amount that I am fully willing to lose, let the grid strategy run and regularly pull out any profits. I've had several accounts get blown out, but I took out way more profits than I lost to the blown accounts. I expect to lose the account at some point. That's included as part of the strategy. Overall, I've made a decent profit using grid strategies. I believe it's valuable to have it as part of your trading portfolio, but I wouldn't recommend it as the bulk of your trading efforts due to it's inherent unpredictability and erratic cash flow.
Not all of my grid trading accounts have blown up. I have some accounts that have been running profitable grid trading strategies for several years now. They have been close to getting blown out and have had significant drawdown, but they did recover and generate a nice profit. However, I still treat them as if I could lose the whole account at any time and regularly pull out any profits.
I code my own EAs, but my grid trading EAs are similar to some free EAs and some commercial EAs that I have used in the past. There's nothing wrong with these other commercial EAs, I just prefer to trust my money to code that I have written and fully understand.
For those that are interested in automated Grid Trading I'd recommend the following:
1) Blessing 3
(http://www.jtatoday.info/wiki/index.php?title=Main_Page)
There is plenty of information on the Internet about Blessing 3. You can download it for free and there is a very comprehensive manual and several recommended settings for different pairs. I don't have any experience with their commercial products, but would assume that they are similar to the Blessing strategy.
2) PipStrider
(http://www.forex-goldmine.net/showcase#tab2)
This EA is a fairly simple grid trader that has done very well for me in the past.
3) RoboMiner
(http://www.forex-goldmine.net/showcase#tab1)
This is a very solid and well documented grid trader.
The people who sell RoboMiner and PipStrider are quite smart and fully support their products. I've been very impressed with them. You can register on their website, for free, and download the EAs and run them on a Demo account for as long as you want. Seriously? How many other commercial EA providers let you do that? I'd highly recommend downloading them and running them on multiple demo accounts for at least a month. It won't cost you anything other than your time to see if these EAs will work for you.
If you spend some time to really understand how they work, what the risks are, and regularly pull out profits from your accounts, grid trading can be a nice addition to your trading portfolio. You can reasonably expect to make 2%-6% a month using sensible settings and risk levels.
Good luck in all your trading.
Dozer
) and for the last 8 mths or so, I have been offsetting them with profitable trades taken with Steve's EA's (The Beast helped greatly with this) and the occasional manual trade based on various strategies. 
