We bought this after using a Medela Harmony handheld pump, which fell apart (rubber valves got torn) after only 4 weeks. If you need to express constantly like we did- our little one just wouldn't suckle directly- then you need a 'hospital-grade' pump, and this is the one to buy.
The handheld ones may be good for casual users, but for regular users the moving parts will soon wear out, valves tear and rubber bits fray; and as we found out, replacement parts are a nightmare to obtain. There are other 'hospital grade' pumps out there, but they're all much more expensive than this one- mainly because of all the bell and whistles which you're not likely to need anyway.
We used this regularly, twice a day, for 7 months without a single complaint. It's in the loft now, awaiting the next li'l 'un. Top marks for price, top marks for function, this is the pump for the regular user.