Do credit scores mean anything???

im due to apply for a mortgage in the next week however i got my credit report from experian and it came out at 716 which is what they class as poor???

I have no missed or late payments, no defaults, ccjs or anything. i have 3 credit accounts - my mobile phone which is always up to date. my credit card and a next directory account that i have never used but it says settled. been at the same address for 5 years and registered on the electoral role. so my question is will the actual score affect my chances of getting a mortgage or is it more about the detail? i have £455 balance on my credit card and my limit is due to be upped from £500 to £1100 in a week - i have a letter from the credit card company that says this. im worried because experian has rated me as poor that the banks are going to look at this and think forget it??? or am i worrying over nothing? the negative factors on the report are due to the limit on my credit card is low, which i would of thought was a good think and the fact that im using 98% of my allowance on the card although that will be 50% in a week due to the limit being increased. should i pay off some of the credit card or does the rating that experian give not really matter?

any advice would be appreciated:)