If you disable the FSX stock traffic then you'll probably see an improvement; especially since WOAI packages do not invoke the jetways (by default).
Although WOAI comes with some GA I would suggest downloading the FSX GA package from here:
http://www.flightsim2004-fanatics.com/u ... _GA_DL.htmThere will be a hit with the FSX GA as some are detailed and flyable but the tradeoff is mostly GA free airports without...you can pick and choose packages in the event all at once are too much of a hit.
If you don't already know, you need to decide which flight plan format you wish to use (either FS9 or FSX). WOAI flight plans are by default in FS9 format. If you wish to use FSX format you will need to convert each flight plan. If FS9 format is ok then make sure to download the FS9 format of the FSX GA from the link above.
One last piece of advise, I suggest you take the time to review the wing_span = value for each aircraft.cfg file. My experience with WOAI packages is that 50% have incorrect values and some are off by enough to change the small to medium or reverse. This can cause problems with the fuel truck and location of where the AI park at the airport.
http://www.flightsim2004-fanatics.com/F ... Values.htm