Just to give an update, I went to install them last night, and can confirm a nice drop in the front. I'm not sure if I read online incorrectly that 02-03 WRX top hats work fine on SF5's, but the rear top hats don't line up. Couldn't use my SF5 top hats as the WRX springs were tapered at the top and the SF5 springs aren't. So, in my case I need new top hats for the rears to fit properly.
Not sure if 04-07 top hats are needed, I swear I read that 02-03's were needed to fit perfectly, and the guy I bought them from said they were an 02.
Had to go back to OEM as the car is a DD and I need it for work. So I won't be swapping mine out for a while now.