I guess it can be a nightmare there... but I must have gone on a good day. I must admit though I did turn up as the doors opened to beat the crowds, but it was still busy.
I had quite a good unstressful experience. I went with a mate to buy an office desk and he had been before so he knew where to head to without following the arrows so we took shortcuts through all the displays dodging the slow pace of everyone else. My mates Spanish is good too so we were able to sort out the right colours and whether is was in stock or not very quickly, we found the assistant very helpful.
As soon as we got down into the warehouse we located the flatpack and accessories fairly quickly... and job done!
So i guess the moral of the story is turn up early, go with someone who has been before and knows where the items are that you want.. and speaks Spanish.
I dont think I would go just to browse to see what they have cos if you follow the route with everyone else you have to pass almost everything in the store and it is very big... so I guess you could end up spending a fortune as you will be seeing things you want all through the store... but I assume thats the reason it was designed like that.