I could never use anything like this. I used cheatengine a while back and sent in legit scores, just enough to get the 1000 points and a few times just to squeak into the top 100 list. I got banned within 2-3 days of doing so. Too much risk, too little reward.
i have 30mb/s internet speed and a quad core processor. The refresh times are no issue. Realistically, I can refresh the page manually about 2-3 times per second. Should have no issues keeping up with the program, It's just a matter of what's a good speed to snipe items while not getting frozen.