Well as long as you used good parts (meyle, lemforder, or genuine) then you should be fine, and they'll last many years just like the original ones.
If you've used cheap ones then you may be under there again sooner that you wish. I had fitted some cheap ones all round (i got them from ebay for £140 iirc) and they lasted about 3-4 months, the car was MOT'd about 3 months after fitted and they gave an advisory on the top arms on one side, they had already started creaking at that point and started knocking pretty soon after the MOT, and in the process of failing managed to fail in such a way that they killed both front tyres.
So 4.5 months after fitting the first set i had to spend a further £330 on some Meyle arms and install them, plus replace both front tyres at a cost of £120 and get the tracking done again. Trying to save £200 the first time round ended up costing me over £500!