I frequent both web sites.

PB as far as software goes, isn't as bad as it is maligned to be.
It is not as strong as HKN/IS:Boxer, but probably stronger then anything else, as far as features go.
It does receive regular updates, but not nearly as frequent as IS:Boxer.
Like IS:Boxer, it is a subscription model (at least sort of); you get a year of free updates, and then have the option of renewing for additional updates or using the version of the software as it currently is.

The issues between Tim and Ellay (MB.com and D-B.com) predate my time, and honestly aren't really my business.
There is animosity between both sites, which sucks since the users of both are all part of the multiboxing/dual-boxing community.