YES!! step away from the credit card!
I had the Xtreme (Giraffe) when DD was born in January. I had it for 7 weeks before the front wheel broke and became wobbly (making it unbearable to push). I was using it maybe 2 or 3 times a week so not even excessively.
I would also like to point out how crap Mothercare are. When I put my Xtreme in for repair (which I was told would take a month minimum) they gave me a loan buggy to use. It was a Silver Cross stroller (the hideous one with pink butterflies all over it because they "thought I'd like something girlie" 
I took DD to a shopping centre, got her out of the car, strapped her in, turned round to get her blanket out of the car and IT BLEW OVER backwards with her in it. Had I not already strapped her in, it would have been her head on the concrete.
I went straight to Mothercare in the shopping centre to get a proper pushchair replacement, not just a stroller. The only two they had at that store were broken! They tried to get me to take one anyway. I was told that if I wanted a refund for the Xtreme so I could buy a suitable replacement that I had to go to the store I gave my Xtreme for repair.
So still in a rage, I got back in the car and went to the other store and demanded my money back. I had to argue and fight for this and got no apology for what happened to DD - I was told that the buggy was suitable for her age and she shouldn't have been left unattended in it ((I was stood right next to her)!
I eventually got my money back and wrote a formal complaint to Mothercare, to which I got a generic response that they would pass my comments on to the store manager(s). It was only after I wrote a complaint on their Facebook page that someone got in touch and took my complaint "officially" (as they put it).
I would never buy another Mothercare product after that experience!