I'm looking for shoe advice. I found the Nike Katana's online for about $40 but I don't like getting shoes online that I haven't already tried out. What are the Katana's like? I am currently using the Fila Corso's (yeah, it's been a few years since I got new racers). I like them but have a lot of miles on them. I've also used the Saucony Fasttwitch which were good. I'm about 145 to 150 lbs. and run mid 2:40 for a marathon. Any experiences with the Katana's or something else I should be looking for?