I've seen it and it isn't right. The charts look like the Mag7 and 1260 are neck and neck, but not even close. I've read that all the ratings are based on 50 Hz and the reason that you get more flow is the USA 60Hz, but I dont know if that is true. I know part of it is the Mag ratings are at 0' and they really lose a lot once you add the typical 4'+ of head to it. The Eheim loses very little flow.
You can either put a valve on the 1260 to dial it back some if needed or go with a 1250. I've never used a 1250, so I dont really know the actual flow. If I had to guess maybe more like a mag5?