Pure wool is said by some to last less well than ones that are, say, 20% synthetic, but Persian carpets are often pure wool (or else a wool with silk pattern - never any synthetics) and last extremely well. In my experience, once the pile becomes longer than the classic type, then the carpet looks tired sooner. Genuine Axmister is very good - we have a light coloured one (80/20, I think) in our lounge which is now over 3 years old and it looks the same as it did when it was laid. Mind you, we never wear outdoor shoes in the house and insist no-one else does - no brushing vacuum only suction. We also have Persians which have had a lot of use (25 years plus) and the cheapest ones are showing wear but look nice all the same, while the most expensive one looks as good as when we bought it. Finally, there is some old woolen carpet (60 years or so old) where we are in the process of refurbishing - while it certainly shows wear, it has held up extremely well. I recommend high wool content and a choice of densely woven standard pile length - you will be charged for this but it is well worth it. But for the longevity choose a coulour (fairly soft, unstriking) and pattern (none really) which is not going to tire your sight of it.