Sven's England sides invariably went backwards after half-time. He had his moments and we haven't drubbed a top side since we murdered Germany 5-1 in Munich 9 years ago.
Top sides are very rarely drubbed though so it's not really a fair comparison. How many four or five goal victories against top class opposition have Italy or Spain had?
Under Sven we beat Argentina (twice), Croatia (something that eluded his successor - twice) and the afore-mentioned Germany. More to the point, we only lost three competitive matches in six years - and two of those were to France and Brazil.
I personally believe that England will never again reach three successive QFs in major tournaments in my lifetime - not without a major structural overhaul.