Maybe the fact that they both offer over 30+ GB of disk space and 750+ GB of bandwidth for less than $10 per month. The overselling in the industry is getting ridiculous, one day I'm going to sign up for 2-3 of these hosting plans and fill up each account. I'd be curious to see if they kick me out for using too many resources
What I would recommend you do is spend a few days reading the Bluehost forum. It would be advisable to check it several times daily so you don't miss something that gets deleted. If after you've done this you still have interest, may The Force be with you.
Been with bluehost for a year, recently had a billing mixup with my bank, instead of contacting me and giving me a chance to rectify the problem, they cancelled my account and deleted my entire site, emails and all.
If these two companies are owned by the same people, they'll most probably extend the same courtesy towards their customers, so i would recommend looking elsewhere