This lens is a bit of a sleeper as its quite cheap but does give quite good image quality once past F4. I recently decided to go with primes for all lenses under 100 mm - why carry around a 24-70 that weighs 1.4 kilos when I can get a 50mm, a 28 and a 20 that weigh just about 0.6 kilos between them...
small; light; very sharp centre resolution
some distortion; not particularly robust