It's not the brand that matters. Brooks and Asics and most manufacturers make shoes for varying degrees of pronation and then it just comes down to individual fit and which suits your own individual needs better. For example I tried the Brooks Adrenaline GTS 12 which are supposed to be for overpronators but I couldn't get on with them at all. Personally for me the Asics GT2170 and now the GT2000 seems to be the best shoe for my needs. Not saying Asics is better than Brooks or anything like that... you just need to find what works for you. For me it's been a lot of trial and error!!
I get them quite often on a Sunday evening when I've done a long run or a long-ish race on a Sunday morning. A lot of info on the internet about it if you google "exertion headache". Surprised to find out how many runners it seems to affect.
I've had a similar problem. I've been wearing custom made orthotics for about 3 years now to correct overpronation and an 8mm leg length difference. Recently my shins flared up again and I've noticed that running in my custom made orthotics actually make them feel worse. My leg length difference also seems to have disappeared. I know it's difficult to judge for yourself but it was quite noticeable 3 years ago if I sat against a wall with my legs stretched out in front of me. Currently running in a cheap-ish pair of off the shelf orthotics with neutral shoes. I guess my gait must have changed quite a bit in the 3 years. I think I might try a pair of support shoes next in my desperation to find a long term solution....
They have definitely made a big difference for me but one of the first things that Peter Taylor at Atlas told me was that they're not a miracle cure, I had to do a lot of stretching and strengthening exercises. I still have to do a lot of stretching. I'm now running approx 40-45 miles a week which I could have only dreamed about before. My problem was/is overpronation and a slight leg length discrepancy. My main issue was a shin injury but I used to get a lot of aches and pains particularly from running or just standing up for a few hours. I hardly get any now and if I do have problems now it's usually because my running shoes are wearing out or I've been neglecting my stretching or I've overtrained.
The orthotics did take a bit of getting used to though and the custom ones are expensive. Mine have got to the stage now where they need refurbing which is going to cost another £20-£30!