I also still recommend Brainwavz HM5 pads for anyone not content with the original pads. I cannot say whether they are more or less neutral than the original pads because they're so comfy I don't want to get my ears out of them, but I love how my cans sound, so. ^_^
Not to be confused with the Thick memory foam HM5 pads. I don't know how those are supposed to work with the HM5, but they make my GMs sound way too thin. Nothing like the signature you get with any other pads I tried (including velour DT 770 pads).
And, yes, velour pads soften the bass impact so you may try some of those too, weissglut.
The HM5 pads have arrived and first thing I can say is: they are more comfortable than the original pads because they are real over the ear pads and they are quite soft. Also they look great So far the price is really great, too.
The sound IMHO is still V-shaped. A strong, but not boomy bass. I had to add the foam dust protection, which I had lying around somewhere (http://www.german-maestro-shop.de/epages/61902279.sf/de_DE/?ObjectPath=/Shops/61902279/Products/%22Staubschutz%2018-6090%22). Without it there is a really annoying sibiliance in the highs.
The over all clarity of the Beyer T70p is not reached, but that does not matter for me. I'll keep this cool phones
EDIT: The HM5 pads have a tight fit, but actually it works great.