[almost_no_specifics]

You mean Brooks? I have adrenaline GTS 7... and all I can think is that possibly the difference in cushioning - mine is for fairly pronounce over-pronation. I suggest having a look at their website, you might be able to reap some sort of sense from that.

 

[almost_no_specifics]

Hrmm... well I looked on their site and they only have the 8s on there, so I can only presume that they're a newer model. They don't look any different and from the specs seem as far as I can see exactly the same as the 7s. Plus I only got mine just before xmas.

Who were you recommended 8s by? If it was a specialist running shop advisor person then fair enough... if not then I strongly recommend you go to a running shop and try on the shoes and run for a bit on a tradmill if they have one. If you over-pronate (which is what these shoes are for) then you're best getting the most comfortable shoes you can that support enough, etc etc. A specialist shop will probably be able to tell you if you over-pronate or not. You don't have to buy the shoes there, they tend to hoik the prices up a bit, just take a note of the best ones, and look for the cheapest pair on the net.

 

[almost_no_specifics]

Hrmm, well they'd probably be fine, but all I'd say is see if you can find a pair of 7s somewhere and try them on first. I can't find anything that says how they've changed them, apart from adding the shiney bits heh... so it's best to be sure.