Is it really that much of a change as in night/day? I have generic orthotics right now as prescribed by a podiatrist, and also haven't noticed much change . I was a little upset at the $60 price tag, so I wouldn't be keen on dropping 300, but I guess if it's worth it...?
As the podiatrist will tell you, foot stuff is all about time. The generic inserts I used didn't make my injury any better over the 4 months that I used them, but I also think that they prevented me from getting worse. For Plantar Fasciitis, the best thing to really do is stop running and let my feet heal. I did that for about 3 weeks and felt much much better....then I started running again....and started hurting. Now I'm trying to balance a relatively light load of running with new inserts. Unfortunately it will take me some time to see results. The woman who fitted the inserts for me said if you had PF for 4 weeks, plan on it taking 4 weeks for it to heal. I've had it for 6 months...so I need to be patient.
Bottom line, change your shoes often and don't overtrain. The results are a pain in the ass, well, foot.