Woefully inept is over- egging it - but I can see what you are getting at - and you PnG to a degree.
With Wenger - it always seems sometimes like there's a glass ceiling for his teams that allows them to get so far - to flatter to deceive if you like - only to fall short of proper success. I guess what you are saying, PnG is that while we did undoubtedly show the mental strength, composure and team performance necessary to go through on Wednesday night - Wenger's teams are, and have always been, capable of pulling off a good result - never more so than in getting to our glass ceiling of last 16 CL qualification or top 4 EPL.
I suppose its perfectly valid for both of you to take the view that a 'real performance' would be one that ended up breaking our 'glass ceiling'.
And that's the problem I guess. I was genuinely impressed with us on Wednesday - but without evidence of a proper step up by this team it will be just another of the many causes for optimism that we have had over the years, only to ultimately be let down.