I am not going to pass judgment on either show, but I will say this: From what I can tell, MD is going after a different niche than PBW, and using different growth goals.
Pro Bodybuilding Weekly is going for the mainstream bodybuilding & fitness audience. They got Arnold, they got Sirius, they are looking like a serious media force in the future as they get more face time and coverage with the webcast events. They are here to stay, and establishing a strong foothold in enough areas that they are dependent on none.
MD, on the other hand, is going for a very small, yet perhaps less casual group. They are shooting for the hardcore, animal types that read MD and frequent the message boards. They are more dependent upon the forums- if MD forum attendance falls, their audience falls significantly. PBW, on the other hand, loses a much smaller % of its listener base if getbig fails.
PBW is best for the 20-50 year old fan, following the sport because you like today's greats and greats from years past. The forum is clean and you can listen to it with the family. MD is for the 13-25 group who enjoys profane antics and hit-or-miss attempts at radioic ownings. Higher highs, lower lows.
Interesting is the recent move by MD to 'take on' PBW by banning the link, and all links to BBing.com and others. IMO, competition is NOT what they want at this point, as PBW owns them on market share and growth rate. If I ran MD, I would be doing everything possible to form an amicable relationship with PBW and benefit from the growth of the sport. By closing links to outside boards, they are also closing the influx of listeners. And, pissing off decision makers at the larger organizations.
MD is now in a position where it can only further try to reinforce its renegade niche, as the bridges burned prevent a mutually beneficial relationship with the larger BBing.com/PBW. They've made their bed, so now they should work to ensure the sheets are clean and they meet the needs of their very small niche of listeners. I am curious how they will grow this listener base though - the # of MD mag and board members is much more finite, than PBW's potential audience of all BBing.com readers and webcast viewers, plus Sirius and armed forces network. In other words, MD can have EVERY reader and board member listening, 100% saturation of potentials, and still pale in comparison with the number of casual listeners that the Arnold interview on PBW will grab on Sirius in one week alone. Not a strong position for longterm growth.
It's nothing against either group, just my own analysis looking at both.