I posted a link to SpeedGuide, you might use it to help with your mental breakdown. That would justify the faster connection using cable, something that goes against the usual opinion. It does not explain, however, why he didn d disconnect the slow DSL he has. I said before, speed with cable or DSL depends on a number of factors. As for business cable and DSL, they vary also depending on the company providing it.
Cable generally has the same name, cable, business cable, etc etc.
DSL on the other hand comes in different forms. However, overall they are generally the same speed. One difference that sets them apart though is this. For example, try making a game server. As for DSL, you won't get AS low pings, but you're more likely to maintain that same ping and have less spikes.