Tyre cost and wear is a pretty big topic as you know Bazza but so is grip so when we find someone who has found a good combo, this type of info can be gold. So if you can remember your impressions as the kliks (miles) pass you buy, it'd be pretty handy.
I've just changed to the marathons after using the lazertechs for 2 tyre changes. I wasn't impressed with the how long they lasted.
I'm not sure though how dramatic the effect of riding with a couple of psi lower than specified has on tyre wear cos whilst I'm on top of it now, I found I was caught out a couple of times, making me realise I had to check more often.
So it may well have been me, I don't know.