I have the "Central Pnuematics" brand from Harbor Freight that works great. It holds about 6.5 litre of fluid, and instead of being hand pumped, it hooks to your air compressor to pull a vacuum in the extractor. I've had it about two months now.
I really like the extractpr for doing tranny drains. Before, if the car didn't have a tranny drain plug, I had to put one in - a real PIA. Now, just stick the hose down the dipstick tube and go.
For draining engine block sumps, as to whether an extractor is superior to draining depends on the car.
On my Jag V12, draining the oil gets about 10 qts out; the extractor can pull out 11. On the new Xj8, the extractor can get 6 qts which should be all that is in the sump - I haven't tried to drain this one yet. On my old AJ6 powered Jags, I can drain about 8 qts, but the extractor can only get about 5. On the GTO, the pan must be baffled, as I can drain 6 qts, but the extractor can only get about 1.5 qts out.
It can drain the B&S on the John Deere lawn tractor, the generators, etc., power steering, brakes, etc., and is great for sucking out old gas from equipment so it can be burned.
They are pretty handy devices, and while I normally avoid Harbor Freight stuff, this product works real well.