have been down this road a number of times with many vehicles. Invariably, the cheap ones always work a treat to start off with, usually generating a feeling of intense smugness as you drive down the road, happy in the knowledge you've saved a few quid.
The feeling lasts the same time as the blades (not long)
The price of the blades seems to relate to how long they work effectively for. Go for good quality every time. Bosch have never let me down, and I've alway been happy with the lifepspan, which seems to be comparable with main dealer.