I wouldn't really call the Landreth light. I ran in them for a while; they seem comparable to the Saucony Trigon Ride. Your standard neutral cushioned trainer.<br><br>
I also raced in the Gel Magic Racers, for about a year. If you're going to replace them, the <a href="http://www.asicsamerica.com/products/product.aspx?PRODUCT_ID=240010093&TITLE_CATEGORY_ID=250001546" target="_blank">Gel Hyper-Speed 2</a> is the current equivalent shoe in the Asics line-up -- but much lighter. I almost bought a pair at the Boston expo, but instead opted for the <a href="http://saucony.com/ShoeDetails.aspx?gen=m&use=Race&id=1115&rel=1110,1115,1083,1128,1086,1093,1089,1116,1090" target="_blank">Saucony Grid Type A2</a>, which is also a neutral flat, and just a bit lighter. I've got five marathons on that pair now, and I have no complaints!<br><br>
All other things being equal, a lighter shoe should give you a faster time, if your feet can handle it.