Hey David,
The first and most important check really shouldn’t take any time to collect data. Just grab an EA from EA studio and compare the trade journal in EA studio (using the imported broker data) with MT4 backtester open prices – certainly cant doubt MT4 backtester. Should only take 10-15 minutes to do that really. This first check should definitely quickly put your mind at ease regarding EA studios backtesting quality (Which is honestly absolutely excellent ;-).
Then you can set that EA on demo and wait to see how it compares with the backtester in a weeks time for the second check.