Oh my god - great question. Ikea is so much better, and half the price!! We had our new kitchen installed last year and used everything from Ikea. A friend spent the best part of £20k on a Magtnet kitchen and the quality and fitting are awful (I didn't tell him this!). I was at his house last week and the cupboard hinges were falling off, the runners were not straight etc. Magnet also have this stupid pricing policy - it's like DFS, they say the kitchen will cost £50k pounds, but you can have it for 75% off. They are like double glazing sales people, they set a crazy high price and then discount like mad. It's really annoying when you just want to know a price.
If you get a good kitchen fitter then the Ikea units are of good quality. The only downside is the way the back of the cabinets are built, which makes it more difficult to fit because of a lack of recess (50-100mm on other cabinets) to put pipes and cables behind. It's not a major issue, just neeeds more skill and planning to install well.
My advice would be to get the units and appliances from Ikea - they deliver everything, very easy to do and great service. Then get the work surfaces from somewhere else (the Ikea ones are OK and are cheap, but you can get a better finish) and get a good fitter to do it for you - I can recommend one.
If you'd like photos of our kitchen then PM me, and you can even come and look at it if you want.
We spent about £8-9k in total - and that was full strip back to bare brick, new plumbing (not that much) and wiring, all new appliances, complete new floor (from joists upwards), under-floor heating, new window, all units and worktops, posh tiles and full fitting and install.
Magnet would charge you £20K for all that and from what I've seen, their quality is not good.